Lesion-produced telencephalic catecholamine imbalances and altered operant pecking rates in pigeons

Pigeons with bilateral neurotoxic or electrolytic lesions within ventral mesencephalon, in nucleus tegmenti pedunculo pontinus (TP) (equivalent to substantia nigra) or area ventralis of Tsai (AVT), were found to have catecholamine (CA) depletion in the telencephalon, including the paleostriatum augmentatum (PA) and lobus parolfactorius (LPO), avian basal ganglia rich in CA. Joint telencephalic concentrations of dopamine (DA) and norepinephrine (NE) within individuals were found to vary with sustained fixed interval (FI) pecking rate increases or decreases following surgery. Low (below 75% of controls) DA/normal NE concentrations were found in individuals showing a marked reduction in their key pecking rates; low DA/low NE concentrations were found in individuals showing a marked increase in their pecking rates. The fit of these data with the NE-DA interaction hypothesis of Antelman and Caggiula [2] was acknowledged but the nature of that interaction remains to be clarified.