siyahposht khachaki A, sheibani V, Afarinesh khaki M R, sheikhkanloui milan H, shamsizadeh A. Effect of sensory deprivation and Locus Coeruleus (LC) electrical stimulation on the response properties of layer IV barrel cortex neurons in male rats. Physiol Pharmacol 2010; 13 (4) :404-415
URL:
http://ppj.phypha.ir/article-1-575-en.html
Abstract: (11359 Views)
Introduction: Barrel cortex of rodents is responsible for sensory information processing from muzzle whiskers.
Locus coeruleus (LC) as the main source of norepinephrine (NE) in the cortex, is effective on the sensory information
processing.
Methods: Rats were divided to 2 groups. One group underwent sensory deprivation (P4) and the other group served
as control and did not undergo sensory deprivation. Response properties of the neurons were evaluated by extracellular
single unit recordings following a controlled mechanical deflection of the principal whisker (spared whisker), or before
the simultaneous deflection of principal and adjacent whiskers (trimmed whisker) were assessed. In the P4 group, all
whiskers on the left muzzle, except D2, were trimmed every other day for two months. In both groups, LC was
electrically stimulated 0, 50, 100, 200, 400 and 800 ms before controlled principal whisker deflection. Response
magnitude, latency and CTR index (lateral inhibition index) were assessed.
Results: In the P4 group, deflection of the principal whisker without LC electrical stimulation, increased the
response magnitude and CTR index, but decreased the response latency compared to the control group. The magnitude
of the response of neurons to the principal whisker deflection was significantly different between P4 and control groups,
in following of principal whisker deflection in times of LC stimulation showed significant difference only in 50 ms
subgroup. In both groups, pro-stimulation differences in CTR index and response latency remained unchanged after LC
stimulation.
Conclusion: Our data showed that electrical stimulation of LC following sensory deprivation modulates neuronal
response properties and changes their response pattern.