Ferenc Erdélyi - Academia.edu (original) (raw)

Papers by Ferenc Erdélyi

Research paper thumbnail of GABAergic phenotypic differentiation of a subpopulation of subventricular derived migrating progenitors

European Journal of Neuroscience, 2004

Olfactory bulb interneurons are continuously generated throughout development and in adulthood. T... more Olfactory bulb interneurons are continuously generated throughout development and in adulthood. These neurons are born in the subventricular zone (SVZ) and migrate along the rostral migratory stream into the olfactory bulb where they differentiate into local interneurons. To investigate the differentiation of GABAergic interneurons of the olfactory bulb we used a transgenic mouse which expresses green fluorescent protein (GFP) under the control of the glutamic acid decarboxylase 65 kDa (GAD65) promoter. During development and in adulthood GFP was expressed by cells in the SVZ and along the entire length of its rostral extension including the distal portion within the olfactory bulb. The occurrence of GAD65 mRNA in these zones was confirmed by PCR analysis on microdissected regions along the pathway. Polysialic acid neural cell adhesion molecule, a marker of migrating neuroblasts in adults, was coexpressed by the majority of the GFP-positive SVZ-derived progenitor cells. Cell tracer injections into the SVZ indicated that approximately 26% of migrating progenitor cells expressed GFP. These data show the early differentiation of migrating SVZ-derived progenitors into a GAD65-GFP-positive phenotype. These cells could represent a restricted lineage giving rise to GAD65-positive GABAergic olfactory bulb interneurons.

Research paper thumbnail of Hippocampal “cholinergic interneurons” visualized with the choline acetyltransferase promoter: anatomical distribution, intrinsic membrane properties, neurochemical characteristics, and capacity for cholinergic modulation

Frontiers in Synaptic Neuroscience, 2015

Release of acetylcholine (ACh) in the hippocampus (HC) occurs during exploration, arousal, and le... more Release of acetylcholine (ACh) in the hippocampus (HC) occurs during exploration, arousal, and learning. Although the medial septum-diagonal band of Broca (MS-DBB) is the major extrinsic source of cholinergic input to the HC, cholinergic neurons intrinsic to the HC also exist but remain poorly understood. Here, ChAT-tauGFP and ChAT-CRE/Rosa26YFP (ChAT-Rosa) mice were examined in HC. The HC of ChAT-tauGFP mice was densely innervated with GFP-positive axons, often accompanied by large GFP-positive structures, some of which were Neurotrace/DAPI-negative and likely represent large axon terminals. In the HC of ChAT-Rosa mice, ChAT-YFP cells were Neurotrace-positive and more abundant in CA3 and dentate gyrus than CA1 with partial overlap with calretinin/VIP. Moreover, an anti-ChAT antibody consistently showed ChAT immunoreactivity in ChAT-YFP cells from MS-DBB but rarely from HC. Furthermore, ChAT-YFP cells from CA1 stratum radiatum/stratum lacunosum moleculare (SR/SLM) exhibited a stuttering firing phenotype but a delayed firing phenotype in stratum pyramidale (SP) of CA3. Input resistance and capacitance were also different between CA1 SR/LM and CA3 SP ChAT-YFP cells. Bath application of ACh increased firing frequency in all ChAT-YFP cells; however, cholinergic modulation was larger in CA1 SR/SLM than CA3 SP ChAT-YFP cells. Finally, CA3 SP ChAT-YFP cells exhibited a wider AP half-width and weaker cholinergic modulation than YFP-negative CA3 pyramidal cells. Consistent with CRE expression in a subpopulation of principal cells, optogenetic stimulation evoked glutamatergic postsynaptic currents in CA1 SR/SLM interneurons. In conclusion, the presence of fluorescently labeled hippocampal cells common to both ChAT-tauGFP and ChAT-Rosa mice are in good agreement with previous reports on the existence of cholinergic interneurons, but both transgenic mouse lines exhibited unexpected anatomical features that departed considerably from earlier observations.

Research paper thumbnail of GABAergic phenotypic differentiation of a subpopulation of subventricular derived migrating progenitors

European Journal of Neuroscience, 2004

Olfactory bulb interneurons are continuously generated throughout development and in adulthood. T... more Olfactory bulb interneurons are continuously generated throughout development and in adulthood. These neurons are born in the subventricular zone (SVZ) and migrate along the rostral migratory stream into the olfactory bulb where they differentiate into local interneurons. To investigate the differentiation of GABAergic interneurons of the olfactory bulb we used a transgenic mouse which expresses green fluorescent protein (GFP) under the control of the glutamic acid decarboxylase 65 kDa (GAD65) promoter. During development and in adulthood GFP was expressed by cells in the SVZ and along the entire length of its rostral extension including the distal portion within the olfactory bulb. The occurrence of GAD65 mRNA in these zones was confirmed by PCR analysis on microdissected regions along the pathway. Polysialic acid neural cell adhesion molecule, a marker of migrating neuroblasts in adults, was coexpressed by the majority of the GFP-positive SVZ-derived progenitor cells. Cell tracer injections into the SVZ indicated that approximately 26% of migrating progenitor cells expressed GFP. These data show the early differentiation of migrating SVZ-derived progenitors into a GAD65-GFP-positive phenotype. These cells could represent a restricted lineage giving rise to GAD65-positive GABAergic olfactory bulb interneurons.

Research paper thumbnail of Hippocampal “cholinergic interneurons” visualized with the choline acetyltransferase promoter: anatomical distribution, intrinsic membrane properties, neurochemical characteristics, and capacity for cholinergic modulation

Frontiers in Synaptic Neuroscience, 2015

Release of acetylcholine (ACh) in the hippocampus (HC) occurs during exploration, arousal, and le... more Release of acetylcholine (ACh) in the hippocampus (HC) occurs during exploration, arousal, and learning. Although the medial septum-diagonal band of Broca (MS-DBB) is the major extrinsic source of cholinergic input to the HC, cholinergic neurons intrinsic to the HC also exist but remain poorly understood. Here, ChAT-tauGFP and ChAT-CRE/Rosa26YFP (ChAT-Rosa) mice were examined in HC. The HC of ChAT-tauGFP mice was densely innervated with GFP-positive axons, often accompanied by large GFP-positive structures, some of which were Neurotrace/DAPI-negative and likely represent large axon terminals. In the HC of ChAT-Rosa mice, ChAT-YFP cells were Neurotrace-positive and more abundant in CA3 and dentate gyrus than CA1 with partial overlap with calretinin/VIP. Moreover, an anti-ChAT antibody consistently showed ChAT immunoreactivity in ChAT-YFP cells from MS-DBB but rarely from HC. Furthermore, ChAT-YFP cells from CA1 stratum radiatum/stratum lacunosum moleculare (SR/SLM) exhibited a stuttering firing phenotype but a delayed firing phenotype in stratum pyramidale (SP) of CA3. Input resistance and capacitance were also different between CA1 SR/LM and CA3 SP ChAT-YFP cells. Bath application of ACh increased firing frequency in all ChAT-YFP cells; however, cholinergic modulation was larger in CA1 SR/SLM than CA3 SP ChAT-YFP cells. Finally, CA3 SP ChAT-YFP cells exhibited a wider AP half-width and weaker cholinergic modulation than YFP-negative CA3 pyramidal cells. Consistent with CRE expression in a subpopulation of principal cells, optogenetic stimulation evoked glutamatergic postsynaptic currents in CA1 SR/SLM interneurons. In conclusion, the presence of fluorescently labeled hippocampal cells common to both ChAT-tauGFP and ChAT-Rosa mice are in good agreement with previous reports on the existence of cholinergic interneurons, but both transgenic mouse lines exhibited unexpected anatomical features that departed considerably from earlier observations.