Objective: 

Barrel cortex rats is responsible in sensory information processing from facial whiskers. Locus coeruleus (LC) has influence in sensory information processing. In this study, the effect of phasic electrical stimulation of LC on response properties of layer IV barrel cortex neurons following sensory deprivation in male rats was investigated.

Methods: 

Response properties of eighteen neurons in non-sensory deprivation group (control,unplaged) and twenty two neurons in sensory deprivation group P4 (the D2 vibrissa were first plucked on postnatal day 4) with extracellular single unit recordings in following controlled displacement of the principal or adjacent whiskers or all whiskers were assessed. LC was stimulated in interval times 0, 50, 100, 200, 400 and 800 ms before principal or adjacent whiskers controlled deflection and its effect on Latency, Response Magnitude, CTR (latral inhibition index) were assessed.

Results: 

Sensory deprivation (alone) in comparison to control group increased response magnitude and CTR index and also decreased response latency. In P4 group compared to control group showed that LC electrical stimulation 50 ms before principal whisker deflection caused significant increase of response magnitude neurons and increased CTR value was observed in more times LC stimulation (0–400ms) followed toghter whisker deflection(P<0.05). Latency in all of the times LC stimulation followed principal whisker deflection was decreased (P<0.05).

Conclusions: 

These results showed that electrical stimulation of LC following sensory deprivation was caused by the modulation of response properties of neurons and due to the change in their response patterns.