[Functional subdivisions of the guinea pig accessory olfactory bulb revealed by electrophysiology].
OBJECTIVE
To elucidate possible functional subdivisions in the guinea pig accessory olfactory bulb.


METHODS
The guinea pig accessory olfactory bulbs were cut in sagittal slice. Bipolar tungsten electrodes were inserted into anterior or posterior vomeronasal nerve layers and single square-pulses were delivered through the electrodes to activate afferent fibres. Glass microelectrodes were used to record extracellular field potentials of anterior or posterior external plexiform layers.


RESULTS
A single shook of the VNL provoked a characteristic damped oscillatory field potential and the oscillation in the pAOB was more distinct in wave form and longer in duration than those in the aAOB. The stimulation of anterior VNL elicited field potentials exelusively in the anterior region of EPL, whereas shocks to the posterior VNL provoked oscillatory responses only within the posterior EPL.


CONCLUSIONS
The accessory olfactory bulb in the guinea-pig is distinctly segregated into the anterior and posterior subdivisions and an anatomical boundary exists in both regions. The results suggested that there are at least two different input-output pathways in vomeronasal systems.
Yu
Q
Q
Department of Otolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022.
Tokio
S
S
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D004558:Electric Stimulation; D004594:Electrophysiology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009830:Olfactory Bulb / Q000033:anatomy & histology / Q000502:physiology*; D019147:Vomeronasal Organ / Q000502:physiology