The goals of this project are to determine the major features of synaptic plasticity and functional circuitry in the electrosensory lobe (ELL) of mon-nyrid electric fish. The ELL is a cerebellum-like structure where the primary afferent fibers from electroreceptors terminate. The ELL and similar cerebellum-like structures in other fish are adaptive sensory processors in {Date Released: 08/08/1997 Date Printed: 01/15/1998} which memory-like predictions about sensory input are generated and subtracted from current sensory input, allowing the neural responses to unexpected or novel input to stand out more clearly. The predictions are based on prior associations between sensory input and various central signals conveyed by parallel fibers such as corollary discharge signals linked to motor commands. Plasticity at the excitatory synapse between parallel fibers and ELL cells could be the cellular mechanism for the generation of these predictions about sensory input, and such plasticity has now been demonstrated in the in vitro slice preparation by the P.I. and his colleagues. The plasticity is observed after a few minutes of pairing of a presynaptic parallel presynaptic parallel fiber input with a postsynaptic spike. The plasticity is observed after a few minutes of pairing of a presynaptic parallel fiber input with a postsynaptic spike. The plasticity is anti-Hebbian in that pairings in which the postsynaptic spike occurs during the parallel fiber-evoked epsp lead to a depression of the epsp, whereas pairings at other delays lead to enhancement. Indications of associative plasticity at inhibitory synapses were also obtained. This project is focused on the mechanisms and features of these different forms of synaptic plasticity and on the functional circuitry of ELL. ELL cells will be recorded intracellularly in the in vitro slice preparation. The roles of NMDA receptors, nitric oxide, postsynaptic spikes and postsynaptic calcium will be examined along with the effects of various pairing protocols. Circuitry will be investigated both morphologically and functionally at the cell to cell level. The results are expected to enhance our understanding of synaptic plasticity at the cellular level and the role of such plasticity in memory-like functions such as the generation of predictions about sensory input.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Project (R01)
Project #
5R01MH049792-08
Application #
6392031
Study Section
Hearing Research Study Section (HAR)
Program Officer
Anderson, Kathleen C
Project Start
1994-09-30
Project End
2002-04-30
Budget Start
2001-05-01
Budget End
2002-04-30
Support Year
8
Fiscal Year
2001
Total Cost
$267,364
Indirect Cost
Name
Oregon Health and Science University
Department
Type
Schools of Medicine
DUNS #
009584210
City
Portland
State
OR
Country
United States
Zip Code
97239
Meek, Johannes; Yang, Jianji Y; Han, Victor Z et al. (2008) Morphological analysis of the mormyrid cerebellum using immunohistochemistry, with emphasis on the unusual neuronal organization of the valvula. J Comp Neurol 510:396-421
Bell, Curtis C; Han, Victor; Sawtell, Nathaniel B (2008) Cerebellum-like structures and their implications for cerebellar function. Annu Rev Neurosci 31:1-24
Han, Victor Z; Zhang, Yueping; Bell, Curtis C et al. (2007) Synaptic plasticity and calcium signaling in Purkinje cells of the central cerebellar lobes of mormyrid fish. J Neurosci 27:13499-512
Zhang, Jianmei; Han, Victor Z; Meek, Johannes et al. (2007) Granular cells of the mormyrid electrosensory lobe and postsynaptic control over presynaptic spike occurrence and amplitude through an electrical synapse. J Neurophysiol 97:2191-203
Campbell, Holly R; Meek, Johannes; Zhang, Jianmei et al. (2007) Anatomy of the posterior caudal lobe of the cerebellum and the eminentia granularis posterior in a mormyrid fish. J Comp Neurol 502:714-35
Han, Victor Z; Meek, Johannes; Campbell, Holly R et al. (2006) Cell morphology and circuitry in the central lobes of the mormyrid cerebellum. J Comp Neurol 497:309-25
Sawtell, Nathaniel B; Williams, Alan; Roberts, Patrick D et al. (2006) Effects of sensing behavior on a latency code. J Neurosci 26:8221-34
Bell, Curtis C; Meek, Johannes; Yang, Jianji Y (2005) Immunocytochemical identification of cell types in the mormyrid electrosensory lobe. J Comp Neurol 483:124-42
Sawtell, Nathaniel B; Williams, Alan; Bell, Curtis C (2005) From sparks to spikes: information processing in the electrosensory systems of fish. Curr Opin Neurobiol 15:437-43
Han, Victor Z; Bell, Curtis C (2003) Physiology of cells in the central lobes of the mormyrid cerebellum. J Neurosci 23:11147-57

Showing the most recent 10 out of 16 publications