Chronic exposure to nerve growth factor increases acetylcholine and glutamate release from cholinergic neurons of the rat medial septum and diagonal band of Broca via mechanisms mediated by p75NTR.
Basal forebrain neurons play an important role in memory and attention. In addition to cholinergic and GABAergic neurons, glutamatergic neurons and neurons that can corelease acetylcholine and glutamate have recently been described in the basal forebrain. Although it is well known that nerve growth factor (NGF) promotes synaptic function of cholinergic basal forebrain neurons, how NGF affects the newly identified basal forebrain neurons remains undetermined. Here, we examined the effects of NGF on synaptic transmission of medial septum and diagonal band of Broca (MS-DBB) neurons expressing different neurotransmitter phenotypes. We used MS-DBB neurons from 10- to 13-d-old rats, cultured on astrocytic microislands to promote the development of autaptic connections. Evoked and spontaneous postsynaptic currents were recorded, and neurotransmitters released were characterized pharmacologically. We found that chronic exposure to NGF significantly increased acetylcholine and glutamate release from cholinergic MS-DBB neurons, whereas glutamate and GABA transmission from noncholinergic MS-DBB neurons were not affected by NGF. Interestingly, the NGF-induced increase in neurotransmission was mediated by p75(NTR). These results demonstrate a previously unidentified role of NGF and its receptor p75(NTR); their interactions are crucial for cholinergic and glutamatergic transmission in the septohippocampal pathway.
Huh
Carey Y L
CY
Neuroscience Division, Douglas Mental Health University Institute, McGill University, Montréal, Québec, Canada H4H 1R3.
Danik
Marc
M
Manseau
Frédéric
F
Trudeau
Louis-Eric
LE
Williams
Sylvain
S
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D002799:Cholinergic Fibers / Q000378:metabolism; D020667:Diagonal Band of Broca / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D020932:Nerve Growth Factor / Q000008:administration & dosage* / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D020800:Receptor, Nerve Growth Factor / Q000378:metabolism* / Q000502:physiology; D012686:Septal Nuclei / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology
D020800:Receptor, Nerve Growth Factor; D018698:Glutamic Acid; D020932:Nerve Growth Factor; D000109:Acetylcholine