title: Septal GABAergic neurons innervate inhibitory interneurons in the hippocampus of the macaque monkey.
abstract: The septohippocampal projection was visualized in three Macaca mulatta monkeys by anterograde transport of Phaseolus vulgaris leucoagglutinin. Following injections of the lectin into the medial septal nucleus, P. vulgaris leucoagglutinin-labelled fibres were found in the hippocampal complex, mainly in stratum oriens of the CA1 subfield, throughout the CA3 subfield, and in the hilus and stratum moleculare of the dentate gyrus. The majority of labelled axons were varicose, and formed multiple contacts with cell bodies and dendrites of calbindin D28k- and parvalbumin-immunoreactive non-pyramidal cells. GABA immunoreactivity of P. vulgaris leucoagglutinin-labelled axons and their postsynaptic targets was investigated by sectioning varicose axon segments for correlated light and electron microscopy, and processing alternate ultrathin sections for postembedding immunogold staining for GABA. All P. vulgaris leucoagglutinin-labelled boutons examined were GABA-immunoreactive and the majority of them formed symmetrical synapses with GABA-immunoreactive cell bodies and dendrites. The results demonstrate that a GABAergic septohippocampal pathway exists in the monkey, and, similar to the rat, terminates on different types of GABAergic neurons, including the parvalbumin- and calbindin D28k-containing non-pyramidal cells.
authors.affiliation: Department of Functional Neuroanatomy, Hungarian Academy of Sciences, Budapest.
authors.forename: A I
authors.initials: AI
authors.lastname: Gulyás
authors.forename: L
authors.initials: L
authors.lastname: Seress
authors.forename: K
authors.initials: K
authors.lastname: Tóth
authors.forename: L
authors.initials: L
authors.lastname: Acsády
authors.forename: M
authors.initials: M
authors.lastname: Antal
authors.forename: T F
authors.initials: TF
authors.lastname: Freund
mesh_terms: D000818:Animals; D001370:Axonal Transport; D064092:Calbindin 1; D064026:Calbindins; D005260:Female; D006624:Hippocampus / Q000166:cytology* / Q000648:ultrastructure; D007124:Immunoenzyme Techniques; D007395:Interneurons / Q000166:cytology* / Q000648:ultrastructure; D008253:Macaca mulatta; D009474:Neurons / Q000166:cytology* / Q000648:ultrastructure; D010320:Parvalbumins / Q000032:analysis; D010835:Phytohemagglutinins; D011712:Pyramidal Tracts / Q000166:cytology / Q000648:ultrastructure; D064030:S100 Calcium Binding Protein G / Q000032:analysis; D013569:Synapses / Q000648:ultrastructure; D005680:gamma-Aminobutyric Acid / Q000032:analysis*
chemical_list: C576500:Calb1 protein, rat; D064092:Calbindin 1; D064026:Calbindins; D010320:Parvalbumins; D010835:Phytohemagglutinins; D064030:S100 Calcium Binding Protein G; C100156:leukoagglutinins, plants; D005680:gamma-Aminobutyric Acid