Publications by authors named "Hajime Suyama"

Article Synopsis
  • Vasopressin (VP) is important for social memory and affects the olfactory bulb (OB) during social interactions, specifically by modulating olfactory processing to help distinguish similar odors.
  • In experiments, VP was found to reduce the firing rates of mitral cells (MCs) and diminish excitatory responses in another type of neuron, the middle tufted cells (mTCs), but had no effect on MCs.
  • The study demonstrated that VP enhances calcium influx in juxtaglomerular and granule cell layers when stronger odor signals are presented, suggesting that VP increases inhibition through interneuron activity, ultimately improving the ability to differentiate similar smells like rat body odors.
View Article and Find Full Text PDF

Social discrimination in rats requires activation of the intrinsic bulbar vasopressin system, but it is unclear how this system comes into operation, as olfactory nerve stimulation primarily inhibits bulbar vasopressin cells (VPCs). Here we show that stimulation with a conspecific can activate bulbar VPCs, indicating that VPC activation depends on more than olfactory cues during social interaction. A series of in vitro electrophysiology, pharmacology and immunohistochemistry experiments implies that acetylcholine, probably originating from centrifugal projections, can enable olfactory nerve-evoked action potentials in VPCs.

View Article and Find Full Text PDF

The intrinsic vasopressin system of the olfactory bulb is involved in social odor processing and consists of glutamatergic vasopressin cells (VPCs) located at the medial border of the glomerular layer. To characterize VPCs in detail, we combined various electrophysiological, neuroanatomical, and two-photon Ca imaging techniques in acute bulb slices from juvenile transgenic rats with eGFP-labeled VPCs. VPCs showed regular non-bursting firing patterns, and displayed slower membrane time constants and higher input resistances versus other glutamatergic tufted cell types.

View Article and Find Full Text PDF