Related Experiment Videos
Analysis of synaptic events in the mouse accessory olfactory bulb with current source-density techniques
1Department of Physiology, Kochi Medical School, Japan.
Neuroscience
|July 1, 1992
Summary
This study reveals two distinct synaptic current patterns in the mouse accessory olfactory bulb. These currents are primarily mediated by non-N-methyl-D-aspartate receptors, crucial for processing vomeronasal organ input.
Area of Science:
- Neuroscience
- Olfactory System Research
- Synaptic Physiology
Background:
- The accessory olfactory bulb (AOB) is key for processing vomeronasal sensory information in mammals.
- Understanding the precise mechanisms of synaptic transmission within the AOB is crucial for deciphering olfactory processing.
Purpose of the Study:
- To investigate the laminar and temporal distribution of synaptic currents in the mouse AOB.
- To identify the specific neurotransmitter receptors involved in vomeronasal organ-evoked synaptic activity.
Main Methods:
- Current source-density analysis of field potentials in the mouse accessory olfactory bulb.
- Electrical stimulation of the vomeronasal organ.
- Local infusions of excitatory amino acid antagonists (kynurenate, 6-cyano-7-nitroquinoxaline-2,3-dione, D-2-amino-5-phosphonovalerate).
Main Results:
- Two distinct inward membrane currents (sinks) were identified: one in the glomerular layer and another in the external plexiform layer.
- The glomerular layer sink occurred 5.5 ms before the external plexiform layer sink.
- The external plexiform layer sink was blocked by kynurenate and a non-N-methyl-D-aspartate receptor antagonist, but not by an N-methyl-D-aspartate receptor antagonist.
Conclusions:
- The glomerular layer sink is primarily driven by synaptic excitation of mitral cell dendrites by vomeronasal afferent fibers.
- The external plexiform layer sink is mainly mediated by non-N-methyl-D-aspartate receptor activation in granule cell processes via dendrodendritic synapses.