VISUAL DEPRIVATION DECREASES LONG-TERM POTENTIATION IN RAT VISUAL CORTICAL SLICES

VISUAL DEPRIVATION DECREASES LONG-TERM POTENTIATION IN RAT VISUAL CORTICAL SLICES

Berry R L; Perkins A T; Teyler T J

Brain Research

1993

1993-11

A major finding in the visual plasticity literature is that visual deprivation is effective only during an early 'sensitive' period, which is lengthened by dark rearing. Unresolved is whether the visual cortex is in a normally plastic state prior to light stimulation. This cannot be addressed using paradigms employing light exposure to assess plasticity. Several developmental studies have investigated a plastic phenomenon termed long-term potentiation (LTP) in slices from cat (J. Neurophysiol., 59 (1988) 124-141) and rat (Brain Res., 439 (1988) 222-229) visual cortex. Susceptibility to the induction of LTP parallels the period of sensitivity to visual deprivation. This suggests that slices can be used to assay visual cortical plasticity, avoiding light exposure. In the present study, field potentials were recorded from slices of the primary visual cortices of dark-reared (DR) and control (CONT) Long Evans hooded rats (17 to 21 days). Field potential profiles recorded before and 90 min following tetanic electrical stimulation were subjected to current source density analysis, yielding extracellular current sink amplitudes. Tetanus resulted in LTP in both CONT and DR slices, but DR slices were significantly less potentiated. These results indicate that the primary visual cortex of DR animals is not fully plastic, indicating a role for light stimulation in inducing visual cortical plasticity.

cortex; rat; plasticity; depression; period; Neurosciences & Neurology; pathways; induction; long-term potentiation; organization; nmda receptors; evoked-potentials; visual cortex; critical; current source density; dark rearing; monocular deprivation; source density analysis

Journal Article or Conference Abstract Publication

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

99-104

1

628