Classically conditioned lateralized head movements and bilaterally recorded cingulate cortex responses in cats

Abstract

The aim of this study was to determine the effects of classical conditioning on lateralized head movements and bilateral cingulate cortex neural activity in the cat. For this purpose, a differential conditioning paradigm was developed, which allowed for experimental manipulations of the lateral position of the conditioned (CS) and unconditioned stimulus (US). One tone (CS+) was paired with a unilateral medial forebrain bundle (MFB) stimulation US activating the animal and eliciting approach movements, while another tone (CS-) was not. In different experiments, the CS+ was presented to both ears, to one ear only, or to each ear in random order. Differential conditioning was demonstrated as a head turn conditioned response (CR) of greater acceleration and shorter onset latency to the CS+ than CS-. Increases in cingulate cortex evoked responses and multiple unit activity were also greater to the CS+. Experimental manipulations of the US and CS lateralities resulted in specific CR directions of turn and cingulate cortex neural activity asymmetries suggesting brain-side specific responses in simple classical conditioning. The role of MFB activation for behavioral and neural plasticity is discussed. A new biological model for investigating conditioned lateralized behaviors and approach responses, the cat conditioned head turn response, is proposed.