Presentation Title
Inactivation of the Prelimbic Cortex attenuates Operant Responding in both Physical and Behavioral Contexts
Abstract
The recognition of the role of context in the control of both voluntary (instrumental) and involuntary (Pavlovian) behavior has led to major changes in the ways that we approach altering behavior, such as addiction therapies and dieting. Generally, research has focused on the importance of the physical context; however, we now know that context can include things such as cues, internal states, time, etc. Recently, evidence from research using rats has suggested that when a sequence of two instrumental behaviors is required to earn a reinforcing outcome, the first response can be the “behavioral” context for the second response. That is, the second response is performed as a result of having just completed the first response, and the physical context, composed of the surrounding visual, tactile, auditory and olfactory stimuli, is important only for the first response. The present experiments aimed to determine if the prelimbic cortex (PL), which has previously been shown to be important for the effect of the physical, training context on instrumental responses, is also important for behavioral contexts. Rats first learned a heterogenous behavior chain in which the first response (i.e. pressing a lever or pulling a chain) was cued by a discriminative stimulus and led to a second stimulus which cued a second response (i.e. pulling a chain or pressing a lever); the second response led to a sucrose reward. Preliminary results indicate that, when the first and second responses are tested in isolation in the training context, pharmacological inactivation of the PL resulted in a reduction of the first response only. But when the second response was performed in the “context” of the first response (i.e., as part of a behavior chain), PL inactivation reduced the second response. Overall, these results support the idea that the PL is important for mediating the effects of a training context on instrumental responding, whether that training context is physical or behavioral.
Primary Faculty Mentor Name
John Green
Faculty/Staff Collaborators
Mark Bouton (Collaborating Professor), Eric Thrailkill (Collaborating Research Professor)
Status
Graduate
Student College
Larner College of Medicine
Program/Major
Neuroscience
Primary Research Category
Biological Sciences
Secondary Research Category
Health Sciences
Inactivation of the Prelimbic Cortex attenuates Operant Responding in both Physical and Behavioral Contexts
The recognition of the role of context in the control of both voluntary (instrumental) and involuntary (Pavlovian) behavior has led to major changes in the ways that we approach altering behavior, such as addiction therapies and dieting. Generally, research has focused on the importance of the physical context; however, we now know that context can include things such as cues, internal states, time, etc. Recently, evidence from research using rats has suggested that when a sequence of two instrumental behaviors is required to earn a reinforcing outcome, the first response can be the “behavioral” context for the second response. That is, the second response is performed as a result of having just completed the first response, and the physical context, composed of the surrounding visual, tactile, auditory and olfactory stimuli, is important only for the first response. The present experiments aimed to determine if the prelimbic cortex (PL), which has previously been shown to be important for the effect of the physical, training context on instrumental responses, is also important for behavioral contexts. Rats first learned a heterogenous behavior chain in which the first response (i.e. pressing a lever or pulling a chain) was cued by a discriminative stimulus and led to a second stimulus which cued a second response (i.e. pulling a chain or pressing a lever); the second response led to a sucrose reward. Preliminary results indicate that, when the first and second responses are tested in isolation in the training context, pharmacological inactivation of the PL resulted in a reduction of the first response only. But when the second response was performed in the “context” of the first response (i.e., as part of a behavior chain), PL inactivation reduced the second response. Overall, these results support the idea that the PL is important for mediating the effects of a training context on instrumental responding, whether that training context is physical or behavioral.