The brain area controlling movement rhythms and eating in the American cockroach

Surgical removal of the pars intercerebralis (PI) in American cockroaches led to arrhythmicity in locomotor activity and increased food consumption.

• Cockroaches with an ablated PI in constant darkness displayed chaotic locomotor rhythms.
• Increased food intake in ablated PI cockroaches resulted in greater body length and weight.
• No increase in food consumption was observed in cockroaches with an intact PI or those reared under light/dark cycles.
• Elevated levels of digestive enzymes were found in the midgut of cockroaches without the PI, indicating altered digestive activity.
• The findings suggest the PI influences locomotor rhythms and feeding behavior in a way that depends on light conditions.

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