Journal of Comparative Physiology A

, Volume 192, Issue 2, pp 135–150

An in vitro study of long-term potentiation in the carp (Cyprinus carpio L.) olfactory bulb

ORIGINAL PAPER

DOI: 10.1007/s00359-005-0056-7

Cite this article as:
Satou, M., Hoshikawa, R., Sato, Y. et al. J Comp Physiol A (2006) 192: 135. doi:10.1007/s00359-005-0056-7

Abstract

Long-term potentiation (LTP) of synaptic transmission is considered a cellular mechanism for neural plasticity and memory formation. Previously, we showed that in the carp olfactory bulb, LTP occurs at the dendrodendritic mitral-to-granule cell synapse following tetanic electrical stimulation applied to the olfactory tract, and suggested that it is involved in the process of olfactory memory formation. As a first step towards understanding mechanisms underlying plasticity at this synapse, we examined the effects of various drugs (glutamate and GABA receptor agonists and antagonists, noradrenaline, and drugs affecting cAMP signaling) on dendrodendritic mitral-to-granule cell synaptic transmission in an in vitro preparation. Two forms of LTP are involved: a postsynaptic form (tetanus-evoked LTP) and a presynaptic form. The postsynaptic form is evoked at the granule cell dendrite following tetanic olfactory tract stimulation and is suppressed by the NMDA receptor antagonist, D-AP5, enhanced by noradrenaline, and occluded by the metabotropic glutamate receptor agonist, trans-ACPD. The presynaptic form occurs at the mitral cell dendrite following blockade of the GABAA receptor by picrotoxin and bicuculline, or via activation of cAMP signaling by forskolin and 8-Br-cAMP.

Keywords

Long-term potentiationDendrodendritic mitral-to-granule cell synapseOlfactory bulbCarpIn vitro preparation

Abbreviations

ACSF

Artificial cerebrospinal fluid

8-Br-cAMP

8-Bromoadenosine 3′,5′-cyclic monophosphate

C2

Component 2 wave

CNQX

6-Cyano-7-nitroquinoxaline-2,3-dione

D-AP5

D-(-)-2-amino-5-phosphono-valeric acid

DMSO

Dimethyl sufoxide

GABA

γ-Aminobutylic acid

GC

Granule cell

IBMX

3-Isobutyl-1-methylxanthine

iGluR

Ionotropic glutamate receptor

LTD

Long-term depression

LTP

Long-term potentiation

MC

Mitral cell

mGluR

Metabotropic glutamate receptor

NMDA

N-methyl-d-aspartate

OB

Olfactory bulb

OT

Olfactory tract

PPD

Paired-pulse depression

PPF

Paired-pulse facilitation

PTX

Picrotoxin

t-ACPD

trans-ACPD/(±)-1-Aminocyclopentane-trans-1,3-dicarboxylic acid

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.Division of Information Science, Graduate School of Integrated ScienceYokohama City UniversityYokohamaJapan