Modulation of food and water intake by catecholamines injected into the lateral ventricle of the pigeon brain

The effects of noradrenaline, adrenaline and dopamine on food and water intake were investigated in satiated (food ad libitum) adult pigeons weighing 320-360 g (N+10 per group). Catecholamines (80 nmol in 1 ul of saline) were injected into the right lateral ventricle. A significant increase in food consumption during the first hour was induced only by noradrenaline (8.1 ñ 1.8 g) and adrenaline (8.0 ñ 2.7 g) vs 1.9 ñ 0.6 g for the saline control. Noradrenaline also caused a significant drop during the secondar hour (1.7 ñ 0.6 g for the saline control). Dopamine decreased food intake at 2 h (1.4 ñ 0.3 g vs 3.5 ñ 0.7 g for the saline control) and 3 h (1.4 ñ 0.4 g vs 3.2 ñ 0.7 g for the saline control) post-injection, with a subsequent elevation in the feeding response during the 4th h (4.9 ñ 0.9 g vs 2.6 ñ 0.7 gf for the saline control). The total food ingestion for the 6-h period was similar for the control and experimental groups. Water consumption was not significantly affected by any catecholamine during any specific period but total ingestion was increased by noradrenaline (44.7 ñ 3.0 ml vs 29.6 ñ 5.1 ml for the saline control). These results suggest that catecholamines are involved in the neural control of food, but not water, intake in pigeons

Participation de alpha receptors in the neural control of food intake in pegeons

The effects of noradrenaline (NA) on food intake were investigated in 69 satiated (food ad libitum) adult pigeons (320-360 g). NA (30 nmol, N = 10, and 80 nmol, N = 12, in 1 µl NaCl) was injected into the right lateral ventricle. Both doses caused a significant increase in food consumption; the higher dose caused a more prolonged effect. The 30-nmol NA injection induced significant increases in the 1st (from 1.6 to 4.5 g) and 6th (19.4 to 25.9g) hours. The 80-nmol dose caused significant increases from the 1st to the 5th hour (1.6 to 6.8,4.4 to 8.7,7.1 to 10.8,10.1 to 14.1 and 14.9 to 21.0g). Previous intracerebroventricular administration of phentolamine (50 nmol, N = 12), but not of propranolol (100 nmol, N= 13) suppressed food ingestion increased by NA administration, with identical results to those of the control group (N = 22). These results indicate that central adrenergic synapses are likely to be involved in the mediation of food intake regulation

Behavior effects of adrenaline and noradrenaline injected into the lateral ventricles of the pigeon (Columba Livia)

The behavioral effects of intravrnticular 1-micronl injections of adrenaline and noradrenaline (both in a concentration of 30 nmol/micronl) were wxamined in pigeons bearing cannule chronically implanted into the lateral ventricles. Injections of either catcholoamine evoked immediate and intense bouts of feeding behavior, followed by long-lasting incrases in sleep duration (50-90% higher than vehicle-treated subjects) in pigeons given free access to food during the observation period. Pigeons treated with adrenaline or vehicle only, and placed in a cage without the feeder set (food-deprived durngi the observation period), exhibited late increases in exploratory and preening behaviors, and less sleep than controls (vehicle-treated pigeons with free access to food). These data suggest that post-prandial sleep in this situation may represent a by-product of feeding-related processes evoked by both catecholamines