Olfactory reciprocal synapses: dendritic signaling in the CNS.
Synaptic transmission between dendrites in the olfactory bulb is thought to play a major role in the processing of olfactory information. Glutamate released from mitral cell dendrites excites the dendrites of granule cells, which in turn mediate GABAergic dendrodendritic inhibition back onto mitral dendrites. We examined the mechanisms governing reciprocal dendritic transmission in rat olfactory bulb slices. We find that NMDA receptors play a critical role in this dendrodendritic inhibition. As with axonic synapses, the dendritic release of fast neurotransmitters relies on N- and P/Q-type calcium channels. The magnitude of dendrodendritic transmission is directly proportional to dendritic calcium influx. Furthermore, recordings from pairs of mitral cells show that dendrodendritic synapses can mediate lateral inhibition independently of axonal action potentials.
Isaacson
J S
JS
Department of Physiology and Biophysics, University of Washington, Seattle 98195, USA.
Strowbridge
B W
BW
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D001369:Axons / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D003712:Dendrites / Q000187:drug effects / Q000502:physiology*; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D005998:Glycine / Q000494:pharmacology; D066298:In Vitro Techniques; D008959:Models, Neurological; D009543:Nifedipine / Q000494:pharmacology; D009830:Olfactory Bulb / Q000502:physiology*; D018408:Patch-Clamp Techniques; D010455:Peptides / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D020866:omega-Conotoxin GVIA; D020960:omega-Conotoxins
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D010455:Peptides; D011810:Quinoxalines; D016194:Receptors, N-Methyl-D-Aspartate; D020960:omega-Conotoxins; C075851:omega-conotoxin-MVIIC; D013779:Tetrodotoxin; C056723:FG 9041; D015763:2-Amino-5-phosphonovalerate; D020866:omega-Conotoxin GVIA; D009543:Nifedipine; D002118:Calcium; D005998:Glycine