Research Interests:
We study how the brain regulates behaviors and behavioral disorders. Presently, we are focused on elucidating the following:
- Mechanisms responsible for acquisition and regulation of motivated behaviors. Surprisingly little is known about neural plasticity that accompanies experience of motivated behaviors (e.g. sexual, affiliative, and feeding behaviors). For example, sexually experienced animals display sexual efficiency during mating, when compared to those who are naive. This suggests that neural changes occurred during the initial encounter that resulted in this behavioral facilitation. We are presently performing experiments that are elucidating these mechanisms.
- Whether mechanisms that change with experience of motivated behaviors similarly change with exposure to drugs of abuse. That is to say, are the pathways altered with experience of naturally motivated behaviors also subject to alterations with drugs of abuse? Our nervous system has been shaped by natural selection to reinforce behaviors that benefit survival of the individual, and thereby the species. These behaviors include drinking, eating, social interactions, and mating. Drugs of abuse artificially stimulate, or hijack, the same neural mechanisms known to regulate naturally rewarding behaviors. However, for example, not all people who have sex for the first time experience changes that reinforce sexual activity, just like not all people who are exposed to drugs of abuse become addicted. Therefore, understanding these overlapping neural-endocrine mechanisms may benefit our understanding of disorders of motivation, reward, or affect, such as addiction and even depression.
- Mechanisms responsible for impairment of libido that results from taking prescription medications. Many psychoactive drugs, such as antidepressants or anticonvulsants, exert their beneficial influences by acting on neurochemical and neuroendocrine systems that regulate reproductive function, at times to the detriment of this regulation. As a result, patient compliance with the prescribed regimen is often negatively impacted, such that patients will decrease or completely stop drug therapy. Understanding how these drugs act on the neural systems that regulates reproduction is clearly beneficial when designing next-generation approaches to treating these disorders, at a time when dedicated efforts should be undertaken to minimize their side effects or impact on reproductive function.
Techniques:
A major goal in our laboratory is training students to become neuroscientists, specifically behavioral neuroscientists. To this end it is essential that students ask the right questions and engage in the process of critical thinking. However, in addition to formulating the right ideas, students must also have the right tools to help them answer their questions. The following techniques are employed in our laboratory to study neuro-endocrine systems regulating motivation:
- Behavior observation, recording, analyses, and interpretation
- Cannulae implantation
- Enzyme-linked immunosorbent assays (ELISA)
- Immunohistochemical techniques
- Microdialysis, in vivo
- Microinjections (intracranial), using various pharmacological manipulations
- Neurochemical analysis using high performance liquid chromatography (HPLC)
- Neuronal tract tracing techniques
- Neurotoxic, radiofrequency, and electrolytic lesion techniques
- Pharmacological manipulations (central and systemic)
- Spectrophotometry
- Stereotaxic surgical techniques (various)
- Systemic surgical techniques (various)
- Western immunoblotting
- Several other techniques that help us study the brain’s regulation of behavior and its role in behavioral disorders
