Decreasing the cortical response to monocular deprivation need not decrease cell shrinkage in cat lateral geniculate...

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Visual System Plasticity

Background:

• Monocular deprivation (MD) in young animals alters visual cortex function.
• MD leads to cell shrinkage in the lateral geniculate nucleus (LGN).
• The relationship between LGN cell shrinkage and visual cortex response changes is unclear.

Purpose of the Study:

• To investigate if LGN cell shrinkage following MD depends on altered visual cortex cell responses.
• To determine the necessity of cortical response changes for LGN structural plasticity.

Main Methods:

• Comparison of LGN cell shrinkage in three groups of MD kittens.
• One group received lesions of norepinephrine and acetylcholine fibers to the visual cortex.
• This lesioning procedure attenuated MD's effects on visual cortex responses.

Main Results:

• LGN cell shrinkage was observed in all MD groups.
• No significant difference in LGN cell shrinkage was found between control and lesioned groups.
• The procedure to attenuate visual cortex response changes did not alter LGN shrinkage.

Conclusions:

• LGN cell shrinkage following monocular deprivation does not require significant loss of visual cortex cell responses.
• Structural changes in the LGN are not solely dependent on major functional alterations in the visual cortex.