H.elliott Albers - Academia.edu (original) (raw)

Papers by H.elliott Albers

BackgroundEstrogen increases dramatically during pregnancy, but quickly drops below pre-pregnancy... more BackgroundEstrogen increases dramatically during pregnancy, but quickly drops below pre-pregnancy levels at birth and remains suppressed during the postpartum period. Clinical and rodent work suggests that this postpartum drop in estrogen results in an “estrogen withdrawal” state that is related to changes in affect, mood, and behavior. Most studies examining the effect of estrogen withdrawal on the brain have focused solely on the hippocampus.MethodsWe used a hormone-simulated pseudopregnancy model in Syrian hamsters, a first for this species. Ovariectomized females were given daily injections to approximate hormone levels during gestation and then withdrawn from estrogen to simulate postpartum estrogen withdrawal. Subjects were tested for behavioral assays of anxiety and anhedonia during estrogen withdrawal. Following sacrifice, neuroplasticity in oxytocin-producing neurons in the paraventricular nucleus of the hypothalamus (PVH) and its efferent targets was measured.ResultsEstrog...

Hormones and Behavior, 2019

It is widely held that social isolation produces higher rates of mortality and morbidity and has ... more It is widely held that social isolation produces higher rates of mortality and morbidity and has deleterious effects on an individual's sociality. Relatedly, it is widely observed that socially isolated adult rodents display significantly higher levels of aggression when placed in a social situation than do their conspecifics living in social groups. In the following study, we investigated the effects of social isolation on several neurochemical signals that play key roles in the regulation of social behavior in adults. More specifically, we examined the effects of social isolation on vasopressin (AVP) V1a, oxytocin (OT) and serotonin (5-HT)1a receptor binding within the neural circuit controlling social behavior. Male and female Syrian hamsters were housed individually or with two other hamsters for four weeks and were then tested with a same-sex nonaggressive intruder in a neutral arena for 5 min. Social isolation significantly increased aggression in both males and females and altered receptor binding in several brain regions in a sex-dependent manner. For example, V1a receptor binding was greater in socially isolated males in the anterior hypothalamus than it was in any other group. Taken together, these data provide substantial new support for the proposition that the social environment can have a significant impact on the structural and neurochemical mechanisms regulating social behavior and that the amount and type of social interactions can produce differential effects on the circuit regulating social behavior in a sexdependent manner.

The Journal of Neuroscience, 1991

The suprachiasmatic nucleus (SCN), which appears to act as a circadian clock, contains a subpopul... more The suprachiasmatic nucleus (SCN), which appears to act as a circadian clock, contains a subpopulation of local circuit neurons in which vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI), and gastrin releasing peptide (GRP) are colocalized. To determine whether VIP, PHI, and GRP interact within the SCN to produce a signal important for circadian control, the behavioral and cellular effects of coadministration of these neuropeptides were investigated. Coadministration of VIP, PHI, and GRP within the SCN mimicked the phase- delaying effects of light on circadian control following in vivo microinjection and activated SCN single units recorded in vitro. These behavioral and cellular effects of coadministration of VIP, PHI, and GRP were significantly greater than administration of VIP, PHI, or GRP alone or coadministration of any 2 of these peptides. These data illustrate a new mechanism whereby multiple, colocalized neuropeptides interact in a functionally signific...

The Journal of Neuroscience, 1986

A vasopressin-sensitive mechanism within the medial preoptic area- anterior hypothalamus (MPOA-AH... more A vasopressin-sensitive mechanism within the medial preoptic area- anterior hypothalamus (MPOA-AH) appears to be essential for expression of a complex behavior involved in olfactory communication in Golden hamsters called flank marking. The present study investigated whether the induction of flank marking by arginine-vasopressin (AVP) within the MPOA-AH is mediated by a receptor that is more similar to the vasopressor (V1) or the antidiurectic (V2) AVP receptor. Adult male hamsters were anesthetized and implanted with a 26 gauge guide cannula stereotaxically aimed at the MPOA-AH and then microinjected with analogs of vasopressin, oxytocin, and selective V1 and V2 antagonists. Hamsters were tested for flank-marking behavior during a 5 or 10 min observation period following the injection of peptide in a vehicle of 100 nl of saline. None of the 15 analogs of AVP and oxytocin produced more flank marking than the 50.8 +/- 16.2 and 76.8 +/- 4.4 (mean +/- SEM; n = 4) flank marks observed f...

Frontiers in Neuroendocrinology, 2018

Oxytocin (OT) and arginine-vasopressin (AVP) act in the brain to regulate social cognition/social... more Oxytocin (OT) and arginine-vasopressin (AVP) act in the brain to regulate social cognition/social behavior and in the periphery to influence a variety of physiological processes. Although the chemical structures of OT and AVP as well as their receptors are quite similar, OT and AVP can have distinct or even opposing actions. Here, we review the increasing body of evidence that exogenously administered and endogenously released OT and AVP can activate each other's canonical receptors (i.e., cross-talk) and examine the possibility that receptor cross-talk following the synaptic and non-synaptic release of OT and AVP contributes to their distinct roles in the brain and periphery. Understanding the consequences of cross-talk between OT and AVP receptors will be important in identifying how these peptides control social cognition and behavior and for the development of drugs to treat a variety of psychiatric disorders.

American journal of primatology, Jan 24, 2018

Oxytocin (OT) and arginine-vasopressin (AVP) are involved in the regulation of complex social beh... more Oxytocin (OT) and arginine-vasopressin (AVP) are involved in the regulation of complex social behaviors across a wide range of taxa. Despite this, little is known about the neuroanatomy of the OT and AVP systems in most non-human primates, and less in humans. The effects of OT and AVP on social behavior, including aggression, mating, and parental behavior, may be mediated primarily by the extensive connections of OT- and AVP-producing neurons located in the hypothalamus with the basal forebrain and amygdala, as well as with the hypothalamus itself. However, OT and AVP also influence social cognition, including effects on social recognition, cooperation, communication, and in-group altruism, which suggests connectivity with cortical structures. While OT and AVP V1a receptors have been demonstrated in the cortex of rodents and primates, and intranasal administration of OT and AVP has been shown to modulate cortical activity, there is to date little evidence that OT-and AVP-containing ...

Psychoneuroendocrinology, Jan 21, 2018

The rewarding properties of social interactions play a critical role in the development and maint... more The rewarding properties of social interactions play a critical role in the development and maintenance of social relationships, and deficits in social reward are associated with various psychiatric disorders. In the present study, we used a novel Operant Social Preference (OSP) task to investigate the reinforcing properties of social interactions under conditions of high or low reward value, and high or low behavioral effort in male Syrian hamsters. Further, we investigated the role of oxytocin (OT) in a key structure of the mesolimbic reward system, the ventral tegmental area (VTA), in mediating the reinforcing properties of social interaction. Adult male hamsters were placed in a three-chambered apparatus, and allowed access to either a social chamber containing an unrestrained conspecific or a non-social chamber, by pushing through a one-way entry, vertical-swing door. Increasing the duration of social interaction (reward value) decreased the frequency of entering the social int...

Psychoneuroendocrinology, 2016

Social reward plays a fundamental role in shaping human and animal behavior. The rewarding nature... more Social reward plays a fundamental role in shaping human and animal behavior. The rewarding nature of many forms of social behavior including sexual behavior, parental behavior, and social play has been revealed using well-established procedures such as the conditioned place preference test. Many motivated social behaviors are regulated by the nonapeptides oxytocin (OT) and arginine vasopressin (AVP) through their actions in multiple brain structures. Interestingly, there are few data on whether OT or AVP might contribute to the rewarding properties of social interaction by their actions within brain structures that play a key role in reward mechanisms such as the ventral tegmental area (VTA). The goal of the present study was to investigate the role of OT and AVP in the VTA in regulating the reward-like properties of social interactions. Social interactions between two male hamsters reduced a spontaneous place avoidance in hamsters injected with saline control. Interestingly, howeve...

Frontiers in neuroendocrinology, Jan 25, 2016

Virtually every neuron within the suprachiasmatic nucleus (SCN) communicates via GABAergic signal... more Virtually every neuron within the suprachiasmatic nucleus (SCN) communicates via GABAergic signaling. The extracellular levels of GABA within the SCN are determined by a complex interaction of synthesis and transport, as well as synaptic and non-synaptic release. The response to GABA is mediated by GABAA receptors that respond to both phasic and tonic GABA release and that can produce excitatory as well as inhibitory cellular responses. GABA also influences circadian control through the exclusively inhibitory effects of GABAB receptors. Both GABA and neuropeptide signaling occur within the SCN, although the functional consequences of the interactions of these signals are not well understood. This review considers the role of GABA in the circadian pacemaker, in the mechanisms responsible for the generation of circadian rhythms, in the ability of non-photic stimuli to reset the phase of the pacemaker, and in the ability of the day-night cycle to entrain the pacemaker.

Journal of biological rhythms, 2016

Physiology & Behavior, 1986

Golden hamsters communicate dominance status by flank marking, a behavior that is dependent upon ... more Golden hamsters communicate dominance status by flank marking, a behavior that is dependent upon vasopressin-sensitive neurons in the anterior hypothalamus-medial preoptic area (AH-MPOA). The purpose of the present study was to investigate whether arginine vasopressin (AVP) and an antagonist of AVP could alter or reverse dominant/subordinate relationships in pairs of hamsters. Microinjection of AVP into the AH-MPOA of subordinate hamsters dramatically increased their flank marking despite the presence of their dominant partners. Conversely, microinjection of the AVP antagonist into the AH-MPOA of dominant hamsters blocked flank marking in the presence of their subordinate partners. Surprisingly, the untreated subordinate hamsters significantly increased their own flank marking when tested with their dominant partners treated with the AVP antagonist, thereby reversing the pattern of flank marking normally seen in dominant/subordinate relationships. However, the effect of AVP and the AVP antagonist were limited to the day of treatment. When flank marking behavior was reversed in a pair of hamsters by treatments for three consecutive days, the pair immediately displayed the original dominant/subordinate behavior when treatment was stopped. Anterior hypothalamus-medial preoptic area Scent marking Flank marking (l-Deaminopenicillamine-2-(O-Methyl)-tyrosine) arginine vasopressin Arginine vasopressin Aggression MANY animals communicate by olfactory signals. The Golden hamster (Mesocricetus auratus) disseminates odors

Peptides, 1996

hormones alter the behavioral response of the medial preoptic anterior-hypothalamus to arginine-v... more hormones alter the behavioral response of the medial preoptic anterior-hypothalamus to arginine-vasopressin. PEPTIDES 17(8) 1359-1363,1996.-In Syrian hamsters (Mesocricetus auratus) arginine-vasopressin (AVP) within the medial preoptic-anterior hypothalamus (MPOA-AH) plays a critical role in the control of a hormone-dependent behavior called flank marking. The present study investigated whether ovarian hormones influence flank marking by altering the response of the MPOA-AH to AVP. The amount of flank marking stimulated by microinjection of AVP (9 M in 200 nl saline) into the MPOA-AH varied significantly over the 4 days of the estrous cycle with the lowest levels of flank marking obs,erved on estrus. A second experiment demonstrated that administration of progesterone significantly reduced AVP-stimulated lIank marking in estradiol-treated ovariectomized hamsters. These data support the hypothesis that the changing levels of estradiol and progesterone during the estrous cycle influence flank marking by altering the sensitivity or response of the MPOA-AH to AVP.

Behavioral and Neural Biology, 1983

The circadian organization of locomotor activity was examined in Turkish hamsters while exposed t... more The circadian organization of locomotor activity was examined in Turkish hamsters while exposed to a light-dark (LD) cycle, constant illumination (LL), and following blinding and gonadectomy. Under LD 16:8 the activity rhythm of all hamsters became well entrained with activity beginning approximately 30 rain after dark onset. In contrast, when activity rhythms free-ran as the result of exposure to LL or blinding, a variety of spontaneous perturbations in the period and/or phase of the activity rhythm were observed.

Regulatory Peptides, 1985

Arginine-vasopressin (AVP) microinjected into the medial preoptic area (MPOA) induces flank marki... more Arginine-vasopressin (AVP) microinjected into the medial preoptic area (MPOA) induces flank marking behavior, a form of olfactory communication, in the golden hamster. When exposed to the odors of conspecifics flank marking behavior occurs naturally in association wth grooming of the flank gland region. The present study examined whether microinjection of AVP, oxytocin (OXY) and other biologically active peptides into the medial preoptic area (MPOA), lateral cerebroventricle (LV) or the ventromedial or lateral hypothalamus (VMH-LH) would elicit flank gland grooming. Microinjection of AVP and OXY produced 2-3 times more flank gland grooming when microinjected into the MPOA than saline, neurotensin or angiotensin II. Injection of AVP into the LV and VMH-LH produced significantly less flank gland grooming than when injected into the MPOA. vasopressin; oxytocin; behavioral effects; medial preoptic area; hamster Arginine-vasopressin (AVP) injected into the mammalian CNS has been demonstrated to affect a variety of behaviors (for reviews see Refs. 1,2). In hamsters, an essential role for AVP in flank marking behavior, which is a form of olfactory communication, has been localized within the medial preoptic area (MPOA). Microinjection of AVP, but not other peptides or classical neurotransmitters, into the MPOA

Peptides, 1994

The geniculohypothalamic tract (GHT) is a projection from the intergeniculate leaflet to the supr... more The geniculohypothalamic tract (GHT) is a projection from the intergeniculate leaflet to the suprachiasmatic nucleus (SCN). The GHT exhibits neuropeptide Y (NPY) immunoreactivity and appears to communicate photic information to the SCN. Microinjection of NPY into the SCN has been found to phase shift circadian rhythms of hamsters housed in constant light in a manner similar to the phase shifts produced by pulses of darkness or triazolam injections. In the present study, NPY was injected into the SCN of Syrian hamsters housed in constant darkness and was found to produce phase shifts similar to those seen in hamsters housed in constant light. Microinjections were not followed by wheel running during the subjective day (the time when NPY microinjections are followed by significant phase advances). These data suggest that NPY produces phase shifts by some mechanism other than by inducing wheel running or by inhibiting the response of SCN neurons to light and supports a role for NPY in nonphotic shifting of the circadian clock.

Journal of Biological Rhythms, 1996

The purpose of the present study was to determine whether there is a rhythm in glutamic acid deca... more The purpose of the present study was to determine whether there is a rhythm in glutamic acid decarboxylase (GAD) message in the suprachiasmatic nucleus (SCN) of rats housed in a light:dark cycle. The mRNAs encoding two isoforms of GAD (i.e., GAD65 and GAD67) were examined using in situ hybridization histochemistry. Computerized image analysis of film autoradiographs revealed that GAD65 mRNA was significantly higher in the light than it was in the dark. GAD67 mRNA levels were lower overall and did not decrease significantly in the dark. Following emulsion autoradiography, silver grain counts over individual SCN cells indicated that GAD65 mRNA was highest in the dorsomedial hypothalamus during the light. These data suggest that GAD mRNA varies rhythmically in the SCN and that mRNA levels are regulated differently within SCN subdivisions during the light:dark cycle.

Integrative and Comparative Biology, 1993

Synopsis. The purpose of this paper is to describe our studies focused on the mechanisms by which... more Synopsis. The purpose of this paper is to describe our studies focused on the mechanisms by which hypothalamic neurons process multiple signals and produce an integrated response. We illustrate our research strategy by reviewing our work on two separate neural systems: the hypo? thalamic paraventricular nucleus (PVN) and the suprachiasmatic nucleus (SCN). We have focused on different peptidergic subpopulations within these nuclei to address two issues. In the PVN, we concentrate on the population of neurons containing thyrotropin-releasing hormone (TRH). These neurons are inhibited by thyroid hormones, but activated by cold exposure. Using a molecular approach, we have demonstrated that these conflicting signals simultaneously act on the same population of TRH neurons. This system will continue to be a productive model to study the mechanisms by which neurons process multiple signals. In the SCN, we concentrate on the population of neurons containing vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI) and gastrin releasing peptide (GRP). We have demonstrated that injection of all three peptides into the SCN of hamsters mimics the phase-delaying effects of light on circadian wheel running behavior. In addition, the genes encoding these peptides exhibit different 24-hour profiles of changes in neurons of the SCN. These data support the hypothesis that one mechanism by which these neurons produce an integrated response is by changing the concen? tration ratio of co-released peptides.

European Journal of Neuroscience, 2008

Light information reaches the suprachiasmatic nucleus (SCN) through a subpopulation of retinal ga... more Light information reaches the suprachiasmatic nucleus (SCN) through a subpopulation of retinal ganglion cells that utilize glutamate as a neurotransmitter. A variety of evidence suggests that the release of glutamate then activates N‐methyl‐d‐aspartate (NMDA) receptors within the SCN and triggers a signaling cascade that ultimately leads to phase shifts in the circadian system. In this study, we first sought to explore the role of the NR2B subunit in mediating the effects of light on the circadian system of hamsters and mice. We found that localized microinjection of the NR2B subunit antagonist ifenprodil into the SCN region reduces the magnitude of light‐induced phase shifts of the circadian rhythm in wheel‐running activity. Next, we found that the NR2B message and levels of phospho‐NR2B vary with time of day in SCN tissue using semiquantitative real‐time polymerase chain reaction and western blot analysis, respectively. Functionally, we found that blocking the NR2B subunit with if...