THE EFFECTS OF ANTERIOR MEDIAL FOREBRAIN- BUNDLE LESIONS ON MOTOR-ACTIVITY MOTIVATED BY THE SENSORY DRIVE IN RATS

The orbite-frontal cortex and postcommissural MFB lesions evoked two m ajor effects. The first one consisted in an increased need for light s timulation while the second one concerned changes in anxiety level wit h different results depending on the lesion location (cortical ot subc ortical). The second effect is in agreement with P. Simonov's hypothes is concerning the different configurations of the CNS structures. Upon destruction of the orbito-frontal area, the dominant role in behaviou r regulation is taken over by the <<emotional part>> of the brain, whe reas the destruction of the postcommissural MFB (reduction of the amyg dalar influence on the hypothalamus) creates conditions for functional prevalence of the <<informational brain>>.