Role of Dopaminergic system on food intake-mediated via Ionotropic and Metabotropic receptors agonist of Glutamate in neonatal chicken

Feeding behavior is regulated via a complex network which interacts via diverse signals from central and peripheral tissues. The present study was designed to examine the interaction between glutamatergic and dopaminergic systems on food intake in neonatal meat chicken.

In this study, 264 day-old chicken (ROS 308) were used. In each experiment, chickens divided to 4 experiments including 1 control and 3 treatment groups (n = 11). In experiment 1, chicks ICV injected with normal saline, 6-OHDA (neurotoxin, 2.5 nmol), kainic acid (ionotropic glutamate receptors agonist, 300 nmol) and 6-OHDA + kainic acid. Experiments 2-3 were similar to experiment 1, except injections of the SHC23390 (D1 receptors antagonist, 5 nmol) and AMI-193 (D2 receptors antagonist, 5 nmol) were done instead of 6-OHDA. In experiment 4, saline, 6-OHDA (2.5 nmol), trans-(±)-ACPD monohydrate (metabotropic glutamate receptor agonist, 300 nmol) and co-injection of the 6-OHDA+ trans-(±)-ACPD monohydrate were done. Experiments 5 and 6 were similar to experiment 4, except SHC23390 and AMI-193  were injected instead of 6-OHDA. Then the cumulative food intake measured until 120 min post injection.

Kainic acid significantly decreased food intake (p ≤ 0.05). 6-OHDA and SHC23390 decreased kainic acid and trans-(±)-ACPD- induced hypophagia (p ≤ 0.05).

Interaction between dopaminergic and glutamatergic systems mediates via ionotropic and metabotropic glutamate and D1 dopamine receptors.
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