Tom Gould

Thomas J. Gould

 

Learning and addiction are inked in the brain in unexpected ways, according to Thomas J. Gould, a professor of pharmacology at Temple University. The well-documented learning-related changes in the strength of neuronal connections in the brain not only underlie memory formation and storage but are also affected by drugs of abuse, such as nicotine or alcohol. The goal of Gould's research is to use genetic, pharmacological, behavioral, molecular and electrophysiological techniques to study the effects of these drugs on the neurobiology of learning and memory.  

In 1988, the US Surgeon General concluded that tobacco products are addictive and that nicotine is the main pharmacological agent in tobacco responsible for tobacco's addictive nature.  Many questions remain, however, about nicotine.  It is not completely understood what nicotine's effects on neurological/behavioral function are nor is it understood why nicotine is addictive.  One reason for the incomplete understanding of nicotine addiction may be that addiction is a complex disorder with many factors contributing to the disease.  The symptoms of nicotine withdrawal, which can include physical symptoms, impairments in cognition, and mood dysfunction may be a critical factor in the high relapse rates that occur in cigarette smokers.  Furthermore, genetic factors may modulate the acute, chronic, and withdrawal effects of nicotine on cognition.  Although animal models have provided useful insight into the somatic and affective symptoms of nicotine withdrawal, little animal research has focused on the effects of nicotine withdrawal on learning. 

 Research from Gould's lab uses contextual fear conditioning, a hippocampus-dependent form of classical conditioning, as an animal model for the effects of nicotine on cognition. The goals of the research are: to investigate the effects of nicotine on learning, to identify the cellular and molecular mechanisms that are altered by nicotine use, and to identify genetic factors that may contribute to nicotine-associated neurobehavioral effects.  Our laboratory uses behavioral, pharmacological, genetic, molecular, and electrophysiological approaches to address these questions. 

Nicotine addiction is a disorder that may be maintained by many factors, including nicotine withdrawal-associated deficits in cognitive processes.  One goal of our laboratory is to test pharmacological agents that can potentially reduce nicotine withdrawal-associated deficits in cognition.  Previous research has established that the noradrenergic system is involved in both learning and attention, and recent studies from our lab have demonstrated that nicotine withdrawal-associated deficits in contextual fear conditioning can be reversed by both nicotine replacement and by norepinephrine reuptake inhibitors.  By identifying cellular and molecular processes that can ameliorate the effects of nicotine, more effective smoking cessation strategies can be developed.

The Effects of Alcohol and Nicotine On Cognition 

Alcohol is frequently referred to as a "gateway" substance to nicotine use and abuse, and research has demonstrated that nicotine use in adolescents can predict a transition from social to problem drinking.  However, the reasons for why these two drugs are co-abused remain unclear, although several factors are likely to be involved.  One possible explanation for the co-abuse of nicotine and alcohol is that nicotine may reduce some of the negative symptoms of alcohol, such as disrupted cognition.  Evidence in favor of this explanation comes from studies that have shown that alcohol impairs learning in hippocampus-dependent and independent procedures, while nicotine can reverse these deficits.  An additional goal of our laboratory is to examine the neural substrates underlying the interactive effects of alcohol and nicotine on learning, and also to understand the effects of alcohol on learning when administered alone.  Understanding the interactive effects of these drugs on cognition will aid in developing more effective treatments for both alcoholism and nicotine addiction.