Strick honored for research on brain networks

Peter L. Strick, PhD, the Scientific Director of the Brain Institute, will receive the 2018 Carnegie Science Award for Life Sciences at the Carnegie Music Hall on May 4.  The Carnegie Science Awards program recognizes and promotes outstanding science and technology achievements in Western Pennsylvania.  Strick, the Thomas Detre Professor and Chair of Neurobiology, is being recognized for his fundamental research on brain networks responsible for movement, cognition, and affect.

Among his notable contributions, Strick challenged the classical view of primary motor cortex as the principal source of descending commands for voluntary movement.  His laboratory demonstrated that the frontal lobe contains at least six premotor areas that project directly to the spinal cord.  Each of these cortical areas appears to be uniquely involved in specific aspects of motor control.  Thus, this work established that the neural substrate for the central generation and control of movement consists of multiple parallel pathways descending from the level of the cerebral cortex.

In 1986, Strick and colleagues published a groundbreaking review about basal ganglia circuitry.  They proposed that the basal ganglia participate in five major loops with motor and non-motor areas of the cerebral cortex.  According to this original proposal, the basal ganglia have a major influence not only on the control of movement, but also on cognitive and affective functions.  This review is one of the most cited papers in systems neuroscience (~8,000 citations).  It led to a major paradigm shift in thinking about the normal function of the basal ganglia and their involvement in neuropsychiatric disorders.

To test the proposals about basal ganglia circuitry, Strick pioneered the use of neurotropic viruses for mapping multi-synaptic circuits in the central nervous system of primates.  His studies using viruses as transneuronal tracers provided support for his hypotheses about basal ganglia loops with the cerebral cortex.  In addition, they produced new insights into the function of the cerebellum, another subcortical center.  Strick and colleagues showed that the cortical targets of basal ganglia and cerebellar output include not only the primary motor cortex, but also premotor, oculomotor, prefrontal, posterior parietal, and inferotemporal areas of cortex.  These connections provide the neural substrate for the involvement of the basal ganglia and cerebellum in cognitive processes such as working memory, rule-based learning, switching attention, visual perception and the planning of future behavior.  Furthermore, this work suggests that abnormal activity in these circuits contributes to a broad range of neuropsychiatric symptoms such as those associated with Parkinson's and Huntington's diseases, depression, obsessive-compulsive disorder, attention deficit-hyperactivity disorder and schizophrenia.  Strick’s laboratory has extended these studies to show that the basal ganglia and cerebellum are interconnected at the subcortical level.  These data suggest that the basal ganglia, the cerebellum, and the cerebral cortex are nodes in an interconnected network that operates over multiple functional domains.

Recently, Strick used virus tracing to provide new insights into a classical problem in neuroscience – the brain-body connection.  He showed that cortical areas involved in the control of movement, cognition, and affect are sources of central commands to the adrenal medulla, an organ concerned with immediate responses to stress. These findings provide an anatomical basis for psychosomatic illness, in which how we move, think, and feel has an impact on adrenal function. Overall, his work is helping to dissolve the artificial boundaries between neurology and psychiatry by demonstrating common neural substrates for disorders assigned to each discipline.