Martin Acerbo - Academia.edu (original) (raw)
Papers by Martin Acerbo
These supplementary notes pertain to the Delius, Acerbo, Krug, Lee, and Leydel (2015) paper and s... more These supplementary notes pertain to the Delius, Acerbo, Krug, Lee, and Leydel (2015) paper and summarize some earlier findings about the influence of the environment on the apomorphine (apo) effect, describe the variability of apo effects, the effects of apo infusion, the individual occurrence of apo insensitivity, its indifference with regard to reward conditioning, the hysteresis due to treatment shifts, an extension to the state discrimination account, the effect of a pecking response restraint, a supplement to the conditioning model, some additional remarks regarding the generality of this model and a possible addition to it, a characterization of the response stereotypy, the difficulties with peck type conversions, the relation displacement activities, the occurrence of individual response idiosyncracies, the "mystery" of apo specificity, and a summary of the pharmacological support for the neural model. Introduction. The senior author's group work on the effect of apo (apomorphine) on birds began in 1975 after coming across papers by Amsler (1923), Dhawan and Saxena (1960), and Brunelli et al. (1975) on the pecking occasioned by apo administrations in birds. We first carried out a preliminary, unpublished study on preferences of domestic chicks (Gallus gallus) injected with 1 mg/kg apo i. m. for varying colors of pecking targets, small dots affixed to the walls and floor of their enclosures. This led to a somewhat more extensive study on apoelicited pecking in pigeons (Columba livia; Basten-Krefft, 1977). It was in the course of this latter study that we noticed the sensitization that occurred with repeated apo injections and began to suspect that it might involve a learning process. This led to a series of papers on the subject:
Addendum 2019 to Delius, J. D., & Acerbo, M. J. (2015): The effects of apomorphine in pigeons : Some supplementary notes
Behavioural Pharmacology, 2002
When repeatedly administered a dose of apomorphine (Apo), pigeons, much like rodents, show behavi... more When repeatedly administered a dose of apomorphine (Apo), pigeons, much like rodents, show behavioural sensitization. In birds this sensitization expresses itself as an increasing pecking response to the drug and is found to be partially dependent on the environmental context in which Apo takes efl'ect. In the first experiment we examined what efl'ect difl'erent inter-Apo administration intervals have on the development of Apo sensitization and found that, with some sma ller variations, intervals between 3 hours and 5 days all yielded comparable courses of sensitization. In the second experiment we examined how long pigeons had to be exposed to the same distinct cage to reveal a maximal context-dependent sensitization. Pigeons were therefore repeatedly injected with Apo and consistently placed in an experimental cage for difl'erent lengths of time (5 to 60 min; the overall drug efl'ect lasted for about 1 h) before being returned to their standard home cages. Subsequent tests in the experimental cage and a standard cage showed that 20-min Ilost-injection exposures were sufficient to yield a maximal response in the experimental cage. After training with 20-and 60-min exposures, the pigeons pecked about three times more in the experimental cage than in the standard cage. This confirmed the marked context dependency of the sensitization effect. In the third experiment, groups of pigeons were injected repeatedly with Apo and directly afterwards placed either consistently into the same experimental cage or into different experimental cages. The same-cage group evidenced a significantly much stronger sensitization than the difl'erent-cage group. A cage-habituation group served as a control for the possibility that the weaker sensitization of the different-cage group might be due to a cage novelty efl'ect. This cage-habituation group was run under the same conditions as the difl'erent-cage group but with additional exposures to the crucial cage while injected with saline. This extra treatment did not augment the pecking response to Apo in that cage. In the fourth experiment we examined how long the sensitization to Apo lasts and found that, even after 2 years of drug abstinence, it only waned to 50% of the original asymptotic response. The overall results sUPllort the hypothesis that a very major part of the sensitization to Apo in pigeons is due to a conditioning to the environmental context and to the drug state itself.
Dopamin verursachtes Lernen
39. Tagung experimentell arbeitender Psychologen, 1997
Die Rolle von Dopamin und Glutamat beim assoziativen Lernen der Taube (Columba livia)
Associative learning involves learning a connection between two events (two stimuli or a stimulus... more Associative learning involves learning a connection between two events (two stimuli or a stimulus and a response) after their presentation so that the posterior occurrence of one of them activates the representation of the other. In the present dissertation, two associative learning paradigms are used in order to study the role of the glutamatergic and dopaminergic systems on learning. Apomorphine-induced learning and a simultaneous visual discrimination task are used to assess the participation of both systems mentioned above.Chapter I includes a brief introduction to learning (especially classical conditioning), the use of drugs and of contextual cues as stimuli in this domain. It also treats discrimination learning and colour preferences in birds and in animals in general. The two paradigms used in this work are briefly described in the context of dopamine and glutamate involvement. A brief introduction to dopaminergic and glutamatergic systems introduces the associative learning...
Sodium appetite and cocaine sensitization share similar mechanisms
The FASEB Journal, 2008
Hippocampus and temporal discrimination
7 Chapter I A general introduction 13 Learning and memory 14 Classical conditioning 15 The contex... more 7 Chapter I A general introduction 13 Learning and memory 14 Classical conditioning 15 The context as a CS 16 Drug action as a US 16 Discrimination learning 17 Dopamine in learning 18 The Wickens' learning model 20 The hypothesis 22 Chapter II The glutamatergic and dopaminergic systems. The glutamatergic system Glutamate based transmission 25 Glutamate synthesis 26 Glutamate receptors 26 Glutamate pathways 29 LTP and glutamate NMDA receptors 33 Pharmacology of NMDA receptors 34 The dopaminergic system Dopaminergic based transmission 36 Dopamine receptors 38 Dopamine in the CNS 41 Pharmacology of the dopaminergic system 43 Apomorphine 44 Dopamine in the spinal cord of pigeon 46 Experiment 1 49 Methods 49 Results 50 TH-immunoreactive cells 52 DA-immunoreactive cells 52 DARPP-32-immunoreactive cells 54 Discussion 55 Pre-synaptic membrane 55 Post-synaptic membrane 58 Dopaminergic functionality in the pigeon' spinal cord 59 Chapter III Conditioning induced by apomorphine Introduc...
Behavioural brain research, May 15, 2018
Figure-ground segregation is a fundamental visual ability that allows an organism to separate an ... more Figure-ground segregation is a fundamental visual ability that allows an organism to separate an object from its background. Our earlier research has shown that nucleus rotundus (Rt), a thalamic nucleus processing visual information in pigeons, together with its inhibitory complex, nucleus subpretectalis/interstitio-pretecto-subpretectalis (SP/IPS), are critically involved in figure-ground discrimination (Acerbo et al., 2012; Scully et al., 2014). Here, we further investigated the role of SP/IPS by conducting bilateral microinjections of GABAergic receptor antagonist and agonists (bicuculline and muscimol, respectively) and non-NMDA glutamate receptor antagonist (CNQX) after the pigeons mastered figure-ground discrimination task. We used two doses of each drug (bicuculline: 0.1 mM and 0.05 mM; muscimol: 4.4 mM and 8.8 mM; CNQX: 2.15 mM and 4.6 mM) in a within-subject design, and alternated drug injections with baseline (ACSF). The order of injections was randomized across birds to r...
e-Neuroforum, 2002
Der Verhaltenseffekt der Psychostimulanzien Kokain und Amphetamin, vornehmlich indirekte Dopamina... more Der Verhaltenseffekt der Psychostimulanzien Kokain und Amphetamin, vornehmlich indirekte Dopaminagonisten, steigert sich bei wiederholter Einnahme ein und derselben Dosis. Wahrscheinlich spielt diese Sensitivierung bei der Suchtentstehung eine wichtige Rolle. Mehrfache Gaben vorn direkten, nicht suchtbildenden Dopaminagonist Apomorphin (Apo) führen ebenfalls zu einer Sen si ti vierung. Wir berichten, dass diese Empfindlichkeitssteigerung besonders gut an den Pickanfällen, die Apo bei Vögeln auslöst, untersucht werden kann. Es werden Versuchsergebnisse vorgestellt, die zeigen, dass die Sensitivierung auf einen langwährenden Pawlovschen Lernvorgang zurückgeht. Die Sensitivierung ist ausgesprochen umgetungsspezifisch, auch hinsichtlich der Pick ziele. Einige Besonderheiten der Sensitivierung erklären sich dadurch, dass Apo ein unkonditionierter Reiz ist, der gleichzeitig auch Eigenschaften eines konditionierten Reizes hat. Neuropharmakologische Ergebnisse suggerieren, dass die Sensitivierung auf Apo auf eine synaptische Interaktion zurückgeht, die zu einer Effektivitätssteigerung der glutamatergen Übertragung im ventralen Striatum führt.
Journal of College Science Teaching, 2015
Lab components of undergraduate science courses typically have students complete highly directed ... more Lab components of undergraduate science courses typically have students complete highly directed cookbook-like laboratory activities. These experiences rarely engage students in a meaningful manner and do not accurately convey what the work of science entails. With funding from the Howard Hughes Medical Institute (HHMI), we have created more authentic science research experiences in a variety of undergraduate science courses, including introductory courses. Achieving this among the diversity of freshmen and sophomore science courses-each typically serving hundreds of students on our campus-required careful planning and adaptation. This article describes the many challenges we faced in our effort to create more authentic undergraduate student research experiences and the significant progress we have made in making such experiences more common for our students. Improvements in first-year science, technology, engineering, and mathematics (STEM) retention over the last 2 years suggest that the experiences may be having a positive impact.
Hippocampal lesion and transitive inference: Dissociation of inference-based and reinforcement-based strategies in pigeons
Hippocampus, 2014
A typical nonverbal transitive inference task (TI) consists of several overlapping discrimination... more A typical nonverbal transitive inference task (TI) consists of several overlapping discriminations (A+ B-, B+ C-, C+ D-, D+ E-, where letters indicate stimuli and pluses and minuses denote reinforcement and nonreinforcement). A choice of stimulus B in a novel pair BD is interpreted as indicative of a TI (if B > C and C > D, then B > D). Although hippocampus has been implicated in nonverbal TI, it is not clear whether it simply maintains memory of associative values or stores an ordered representation of stimuli. We investigated the effect of hippocampal lesion on TI in pigeons while controlling reinforcement history so that reliance on associative values would lead to a choice of a stimulus D in the pair BD instead of a choice of a stimulus B expected by inferential mechanisms. Prior to the lesion, some of the pigeons (relational group; n = 4) have selected B over D indicating TI, while other birds (associative group; n = 6) chose D over B suggesting reliance on associative values. Hippocampal lesion had no effect on postlesion performance in associative group. In contrast, the relational group that preferred stimulus B in a pair BD before lesion showed a near-chance performance after the lesion. Our results demonstrate that hippocampus may be involved in creating a representation of an ordered series of the stimuli instead of maintaining reinforcement history of each stimulus. In addition, we provide a behavioral procedure suitable for dissociating different behavioral strategies used to solving TI task. Finally, we show for the first time the involvement of avian hippocampus in the task that is not explicitly spatial in nature. These results further confirm the notion that avian hippocampus is functionally analogous to mammalian hippocampus despite the significant differences in their anatomy.
Behavioural Pharmacology, 2015
Apomorphine (apo), an unspecific direct dopamine agonist, elicits an intense and Iasting pecking ... more Apomorphine (apo), an unspecific direct dopamine agonist, elicits an intense and Iasting pecking bout in pigeons. Apo yielded orderly dose-response functions, and repeated administrations led to sensitization. Strain and individual differences in sensitivity to apo were at least partly due to genetic factors. However, a strong cage-context dependency of the sensitization, which is indicative of conditioning, occurred in both pigeon strains studied. Apo-induced pecking and sensitization also occurred in total darkness. Pigeons could be conditioned to discriminate between an apo state and a non-apo state. A small dose of apowas effective as a conditioned stimulus when paired with a high dose as an unconditioned stimulus. The conditioned response (CR) was strongly specific to the context in which the sensitj_ zation to apo took place. The resistance to extinction of the CR could be increased through an oversensitization treatment. The incremental responses arising during the sensitization treatment and the CRs shown afterward by individual pigeons correlated significantly. The sensitization to apo in lntroduction The repeated adm ini stration of many drugs Ieads to th e development of tolerance-that is, to a progressive diminution of their physiological or behavioral responseeliciting efficacy (Kalant, 1989). T hi s adapti ve process can be v iewed as being part and parcel of a general disposition of organi sms to maintain a relative consta ncy of their milieu interieur (Poulos and Cappell , 1991; Gollwitze r et al., 2000). The widespread occurrence of habitu ation, that is, the reduction of neural or behavioral responses to repeated ly presented exteroceptive stimuli, is an analogaus phenomenon (Groves and T hompson, 1970; Domjan, 1997). This categorization shou ld not be understood as implying that the proximal, physiological processes underlying specific instances of tolerance, or indeed habituation, are straightforward ; whenever investigated in detail , the mechan isms of both tolerance and habituation have turned out to be intricate (cf.
Metabolic Mapping of Brain Structures Involved in Figure-Ground Assignment in Pigeons
PsycEXTRA Dataset
Pharmacology Biochemistry and Behavior, 2005
In earlier studi es it was fo und that glutamatergic tTansmi ssion w ithin the nu cleus accumbens... more In earlier studi es it was fo und that glutamatergic tTansmi ssion w ithin the nu cleus accumbens septi is invo lv ed in th e performance o f a learned visual shape discrimin ation in pigeo ns. This study examin es what effects several kinds of glutamate and dopamine an tagonists have on the same task. Pigeons were trained with the relevant di scrimin ation, bil aterall y implanted wi th cannul as into th e nucleus a ccumbens and tested after vari ous transmi ss ion bl ockers had been administered intracereb rally. SCH-23390, a Dl dopamin e antagoni st, at the dose used, had no effect, and Spiperone, a D2-dopamine and 5HT2a-serotonin e antagonist, significa ntly decreased th e error repeat trials. CNQX, a non-N MDA glutamate receptor antago nist, and Cycl oleucine, an antago nist of the glycine allosteri c site of N MDA receptors, had no effect. CGS-19755, a selecti ve competitive N MDA antagonist, significa ntly impai red perfOlm ance by signifi cantly decreasing the percen t correct trials mid in creas ing the error repea t trials. CPPG, a IIIIII metabotropic glutamate antagonist, remarkab ly improved perfonn ance. MMPG, a n Ull metabotropi c g lutamate antagonist, at the dose used, did not have any signifi cant effect. Th e preparation empl oyed may be a use ful ani ma l model of perceptu al di sturb ances in schizophrenia.
These supplementary notes pertain to the Delius, Acerbo, Krug, Lee, and Leydel (2015) paper and s... more These supplementary notes pertain to the Delius, Acerbo, Krug, Lee, and Leydel (2015) paper and summarize some earlier findings about the influence of the environment on the apomorphine (apo) effect, describe the variability of apo effects, the effects of apo infusion, the individual occurrence of apo insensitivity, its indifference with regard to reward conditioning, the hysteresis due to treatment shifts, an extension to the state discrimination account, the effect of a pecking response restraint, a supplement to the conditioning model, some additional remarks regarding the generality of this model and a possible addition to it, a characterization of the response stereotypy, the difficulties with peck type conversions, the relation displacement activities, the occurrence of individual response idiosyncracies, the "mystery" of apo specificity, and a summary of the pharmacological support for the neural model. Introduction. The senior author's group work on the effect of apo (apomorphine) on birds began in 1975 after coming across papers by Amsler (1923), Dhawan and Saxena (1960), and Brunelli et al. (1975) on the pecking occasioned by apo administrations in birds. We first carried out a preliminary, unpublished study on preferences of domestic chicks (Gallus gallus) injected with 1 mg/kg apo i. m. for varying colors of pecking targets, small dots affixed to the walls and floor of their enclosures. This led to a somewhat more extensive study on apoelicited pecking in pigeons (Columba livia; Basten-Krefft, 1977). It was in the course of this latter study that we noticed the sensitization that occurred with repeated apo injections and began to suspect that it might involve a learning process. This led to a series of papers on the subject:
Addendum 2019 to Delius, J. D., & Acerbo, M. J. (2015): The effects of apomorphine in pigeons : Some supplementary notes
Behavioural Pharmacology, 2002
When repeatedly administered a dose of apomorphine (Apo), pigeons, much like rodents, show behavi... more When repeatedly administered a dose of apomorphine (Apo), pigeons, much like rodents, show behavioural sensitization. In birds this sensitization expresses itself as an increasing pecking response to the drug and is found to be partially dependent on the environmental context in which Apo takes efl'ect. In the first experiment we examined what efl'ect difl'erent inter-Apo administration intervals have on the development of Apo sensitization and found that, with some sma ller variations, intervals between 3 hours and 5 days all yielded comparable courses of sensitization. In the second experiment we examined how long pigeons had to be exposed to the same distinct cage to reveal a maximal context-dependent sensitization. Pigeons were therefore repeatedly injected with Apo and consistently placed in an experimental cage for difl'erent lengths of time (5 to 60 min; the overall drug efl'ect lasted for about 1 h) before being returned to their standard home cages. Subsequent tests in the experimental cage and a standard cage showed that 20-min Ilost-injection exposures were sufficient to yield a maximal response in the experimental cage. After training with 20-and 60-min exposures, the pigeons pecked about three times more in the experimental cage than in the standard cage. This confirmed the marked context dependency of the sensitization effect. In the third experiment, groups of pigeons were injected repeatedly with Apo and directly afterwards placed either consistently into the same experimental cage or into different experimental cages. The same-cage group evidenced a significantly much stronger sensitization than the difl'erent-cage group. A cage-habituation group served as a control for the possibility that the weaker sensitization of the different-cage group might be due to a cage novelty efl'ect. This cage-habituation group was run under the same conditions as the difl'erent-cage group but with additional exposures to the crucial cage while injected with saline. This extra treatment did not augment the pecking response to Apo in that cage. In the fourth experiment we examined how long the sensitization to Apo lasts and found that, even after 2 years of drug abstinence, it only waned to 50% of the original asymptotic response. The overall results sUPllort the hypothesis that a very major part of the sensitization to Apo in pigeons is due to a conditioning to the environmental context and to the drug state itself.
Dopamin verursachtes Lernen
39. Tagung experimentell arbeitender Psychologen, 1997
Die Rolle von Dopamin und Glutamat beim assoziativen Lernen der Taube (Columba livia)
Associative learning involves learning a connection between two events (two stimuli or a stimulus... more Associative learning involves learning a connection between two events (two stimuli or a stimulus and a response) after their presentation so that the posterior occurrence of one of them activates the representation of the other. In the present dissertation, two associative learning paradigms are used in order to study the role of the glutamatergic and dopaminergic systems on learning. Apomorphine-induced learning and a simultaneous visual discrimination task are used to assess the participation of both systems mentioned above.Chapter I includes a brief introduction to learning (especially classical conditioning), the use of drugs and of contextual cues as stimuli in this domain. It also treats discrimination learning and colour preferences in birds and in animals in general. The two paradigms used in this work are briefly described in the context of dopamine and glutamate involvement. A brief introduction to dopaminergic and glutamatergic systems introduces the associative learning...
Sodium appetite and cocaine sensitization share similar mechanisms
The FASEB Journal, 2008
Hippocampus and temporal discrimination
7 Chapter I A general introduction 13 Learning and memory 14 Classical conditioning 15 The contex... more 7 Chapter I A general introduction 13 Learning and memory 14 Classical conditioning 15 The context as a CS 16 Drug action as a US 16 Discrimination learning 17 Dopamine in learning 18 The Wickens' learning model 20 The hypothesis 22 Chapter II The glutamatergic and dopaminergic systems. The glutamatergic system Glutamate based transmission 25 Glutamate synthesis 26 Glutamate receptors 26 Glutamate pathways 29 LTP and glutamate NMDA receptors 33 Pharmacology of NMDA receptors 34 The dopaminergic system Dopaminergic based transmission 36 Dopamine receptors 38 Dopamine in the CNS 41 Pharmacology of the dopaminergic system 43 Apomorphine 44 Dopamine in the spinal cord of pigeon 46 Experiment 1 49 Methods 49 Results 50 TH-immunoreactive cells 52 DA-immunoreactive cells 52 DARPP-32-immunoreactive cells 54 Discussion 55 Pre-synaptic membrane 55 Post-synaptic membrane 58 Dopaminergic functionality in the pigeon' spinal cord 59 Chapter III Conditioning induced by apomorphine Introduc...
Behavioural brain research, May 15, 2018
Figure-ground segregation is a fundamental visual ability that allows an organism to separate an ... more Figure-ground segregation is a fundamental visual ability that allows an organism to separate an object from its background. Our earlier research has shown that nucleus rotundus (Rt), a thalamic nucleus processing visual information in pigeons, together with its inhibitory complex, nucleus subpretectalis/interstitio-pretecto-subpretectalis (SP/IPS), are critically involved in figure-ground discrimination (Acerbo et al., 2012; Scully et al., 2014). Here, we further investigated the role of SP/IPS by conducting bilateral microinjections of GABAergic receptor antagonist and agonists (bicuculline and muscimol, respectively) and non-NMDA glutamate receptor antagonist (CNQX) after the pigeons mastered figure-ground discrimination task. We used two doses of each drug (bicuculline: 0.1 mM and 0.05 mM; muscimol: 4.4 mM and 8.8 mM; CNQX: 2.15 mM and 4.6 mM) in a within-subject design, and alternated drug injections with baseline (ACSF). The order of injections was randomized across birds to r...
e-Neuroforum, 2002
Der Verhaltenseffekt der Psychostimulanzien Kokain und Amphetamin, vornehmlich indirekte Dopamina... more Der Verhaltenseffekt der Psychostimulanzien Kokain und Amphetamin, vornehmlich indirekte Dopaminagonisten, steigert sich bei wiederholter Einnahme ein und derselben Dosis. Wahrscheinlich spielt diese Sensitivierung bei der Suchtentstehung eine wichtige Rolle. Mehrfache Gaben vorn direkten, nicht suchtbildenden Dopaminagonist Apomorphin (Apo) führen ebenfalls zu einer Sen si ti vierung. Wir berichten, dass diese Empfindlichkeitssteigerung besonders gut an den Pickanfällen, die Apo bei Vögeln auslöst, untersucht werden kann. Es werden Versuchsergebnisse vorgestellt, die zeigen, dass die Sensitivierung auf einen langwährenden Pawlovschen Lernvorgang zurückgeht. Die Sensitivierung ist ausgesprochen umgetungsspezifisch, auch hinsichtlich der Pick ziele. Einige Besonderheiten der Sensitivierung erklären sich dadurch, dass Apo ein unkonditionierter Reiz ist, der gleichzeitig auch Eigenschaften eines konditionierten Reizes hat. Neuropharmakologische Ergebnisse suggerieren, dass die Sensitivierung auf Apo auf eine synaptische Interaktion zurückgeht, die zu einer Effektivitätssteigerung der glutamatergen Übertragung im ventralen Striatum führt.
Journal of College Science Teaching, 2015
Lab components of undergraduate science courses typically have students complete highly directed ... more Lab components of undergraduate science courses typically have students complete highly directed cookbook-like laboratory activities. These experiences rarely engage students in a meaningful manner and do not accurately convey what the work of science entails. With funding from the Howard Hughes Medical Institute (HHMI), we have created more authentic science research experiences in a variety of undergraduate science courses, including introductory courses. Achieving this among the diversity of freshmen and sophomore science courses-each typically serving hundreds of students on our campus-required careful planning and adaptation. This article describes the many challenges we faced in our effort to create more authentic undergraduate student research experiences and the significant progress we have made in making such experiences more common for our students. Improvements in first-year science, technology, engineering, and mathematics (STEM) retention over the last 2 years suggest that the experiences may be having a positive impact.
Hippocampal lesion and transitive inference: Dissociation of inference-based and reinforcement-based strategies in pigeons
Hippocampus, 2014
A typical nonverbal transitive inference task (TI) consists of several overlapping discrimination... more A typical nonverbal transitive inference task (TI) consists of several overlapping discriminations (A+ B-, B+ C-, C+ D-, D+ E-, where letters indicate stimuli and pluses and minuses denote reinforcement and nonreinforcement). A choice of stimulus B in a novel pair BD is interpreted as indicative of a TI (if B > C and C > D, then B > D). Although hippocampus has been implicated in nonverbal TI, it is not clear whether it simply maintains memory of associative values or stores an ordered representation of stimuli. We investigated the effect of hippocampal lesion on TI in pigeons while controlling reinforcement history so that reliance on associative values would lead to a choice of a stimulus D in the pair BD instead of a choice of a stimulus B expected by inferential mechanisms. Prior to the lesion, some of the pigeons (relational group; n = 4) have selected B over D indicating TI, while other birds (associative group; n = 6) chose D over B suggesting reliance on associative values. Hippocampal lesion had no effect on postlesion performance in associative group. In contrast, the relational group that preferred stimulus B in a pair BD before lesion showed a near-chance performance after the lesion. Our results demonstrate that hippocampus may be involved in creating a representation of an ordered series of the stimuli instead of maintaining reinforcement history of each stimulus. In addition, we provide a behavioral procedure suitable for dissociating different behavioral strategies used to solving TI task. Finally, we show for the first time the involvement of avian hippocampus in the task that is not explicitly spatial in nature. These results further confirm the notion that avian hippocampus is functionally analogous to mammalian hippocampus despite the significant differences in their anatomy.
Behavioural Pharmacology, 2015
Apomorphine (apo), an unspecific direct dopamine agonist, elicits an intense and Iasting pecking ... more Apomorphine (apo), an unspecific direct dopamine agonist, elicits an intense and Iasting pecking bout in pigeons. Apo yielded orderly dose-response functions, and repeated administrations led to sensitization. Strain and individual differences in sensitivity to apo were at least partly due to genetic factors. However, a strong cage-context dependency of the sensitization, which is indicative of conditioning, occurred in both pigeon strains studied. Apo-induced pecking and sensitization also occurred in total darkness. Pigeons could be conditioned to discriminate between an apo state and a non-apo state. A small dose of apowas effective as a conditioned stimulus when paired with a high dose as an unconditioned stimulus. The conditioned response (CR) was strongly specific to the context in which the sensitj_ zation to apo took place. The resistance to extinction of the CR could be increased through an oversensitization treatment. The incremental responses arising during the sensitization treatment and the CRs shown afterward by individual pigeons correlated significantly. The sensitization to apo in lntroduction The repeated adm ini stration of many drugs Ieads to th e development of tolerance-that is, to a progressive diminution of their physiological or behavioral responseeliciting efficacy (Kalant, 1989). T hi s adapti ve process can be v iewed as being part and parcel of a general disposition of organi sms to maintain a relative consta ncy of their milieu interieur (Poulos and Cappell , 1991; Gollwitze r et al., 2000). The widespread occurrence of habitu ation, that is, the reduction of neural or behavioral responses to repeated ly presented exteroceptive stimuli, is an analogaus phenomenon (Groves and T hompson, 1970; Domjan, 1997). This categorization shou ld not be understood as implying that the proximal, physiological processes underlying specific instances of tolerance, or indeed habituation, are straightforward ; whenever investigated in detail , the mechan isms of both tolerance and habituation have turned out to be intricate (cf.
Metabolic Mapping of Brain Structures Involved in Figure-Ground Assignment in Pigeons
PsycEXTRA Dataset
Pharmacology Biochemistry and Behavior, 2005
In earlier studi es it was fo und that glutamatergic tTansmi ssion w ithin the nu cleus accumbens... more In earlier studi es it was fo und that glutamatergic tTansmi ssion w ithin the nu cleus accumbens septi is invo lv ed in th e performance o f a learned visual shape discrimin ation in pigeo ns. This study examin es what effects several kinds of glutamate and dopamine an tagonists have on the same task. Pigeons were trained with the relevant di scrimin ation, bil aterall y implanted wi th cannul as into th e nucleus a ccumbens and tested after vari ous transmi ss ion bl ockers had been administered intracereb rally. SCH-23390, a Dl dopamin e antagoni st, at the dose used, had no effect, and Spiperone, a D2-dopamine and 5HT2a-serotonin e antagonist, significa ntly decreased th e error repeat trials. CNQX, a non-N MDA glutamate receptor antago nist, and Cycl oleucine, an antago nist of the glycine allosteri c site of N MDA receptors, had no effect. CGS-19755, a selecti ve competitive N MDA antagonist, significa ntly impai red perfOlm ance by signifi cantly decreasing the percen t correct trials mid in creas ing the error repea t trials. CPPG, a IIIIII metabotropic glutamate antagonist, remarkab ly improved perfonn ance. MMPG, a n Ull metabotropi c g lutamate antagonist, at the dose used, did not have any signifi cant effect. Th e preparation empl oyed may be a use ful ani ma l model of perceptu al di sturb ances in schizophrenia.