Suzanne N. Haber, PhD
The Haber lab focuses on the neural network that underlies incentive learning and decision-making that leads to the development of action plans. The cortico-basal ganglia-thalamic system is central to this network and comprises a diverse group of structures involved in reward and motivation, cognition, and motor control. Pathology of this network is implicated in several mental health disorders including drug addition, obsessive-compulsive disorder, and schizophrenia.
One set of questions centers around which pathways are stimulated during deep brain stimulation (DBS). DBS, a proven therapy for intractable tremor and Parkinson disease, is now being actively investigated for depression and obsessive compulsive disorder (OCD), with encouraging results. The electrodes target specific points in the cortico-basal ganglia circuit by placing the electrodes in the internal capsule, ventral striatum (VS), or subcortical white matter. Several ascending and descending fiber bundles pass through these sites, each of which may differentially modulate these behaviors and, thus, the impact on different symptoms. We use 3-D reconstructions of cortical and subcortical pathways and terminal fields to model the electrode and DBS stimulation sites to evaluate how clinical outcome depends on electrode placement.
A second set of experiments address the hypothesis that the cortico-basal ganglia connections are critical for integrating information across functional domains. These complex neuronal networks work in concert with the cortex to moderate behavioral changes and provides the anatomical substrate for plasticity during learning. Specific questions include: 1) what is the organization of cortical and thalamic connections that mediate information flow through the basal ganglia? 2) How are pathways involved in reward processing and cognition integrated into the basal ganglia pathways of action? 3) What is the interface between the descending cortico-basal ganglia system and the midbrain dopamine system?
A third set of experiments is directed towards understanding postnatal changes in the cortico-basal ganglia system associated with specific developmental milestones. A particular focus is on the refinement of cortico-and amygdalo-BG network, including connections, cell types, transmitter systems, and receptors that are consistent with the high level of plasticity during early learning.