Without question, Anna Litmanovich is a “Renaissance woman.” Her first four years of school were spent studying piano in Uzbekistan, the country of her birth. Since coming to the United States, Anna has excelled in both the arts and sciences. For the past six years she has performed for Opera Pacific in Costa Mesa, appearing in nine operas and one ballet. While at UCI, she has investigated the effects of drugs and hormones on memory storage and has tutored students ranging from adopted Russian children who cannot speak English to fellow undergraduates in such fields as math, psychology, physics, and biology. If that’s not enough, she also plays competitive tennis. Anna hopes to pursue a career in academic medicine.

The basolateral amygdala (BLA) is the putative site for integration of neuronal and hormonal signals for emotional learning and memory. The present study explored which muscarinic receptor type(s) (M1, M2 or both) mediates the critical cholinergic activation in the BLA during memory-modulating processes. Sprague-Dawley rats were implanted with bilateral cannulae aimed at the BLA and then trained on an inhibitory avoidance (IA) task. To selectively activate each receptor type, selective antagonists, methoctramine or telenzipine (50 nmol per side), were co-infused with a general muscarinic receptor agonist, oxotremorine, to stimulate M1 or M2 receptors, respectively. Oxotremorine (50 nmol per side) was infused alone to stimulate both receptor types. A single trial IA task was used in combination with immediate post-training drug treatments so that the consolidation phase of memory could be selectively manipulated. The mean retention latency of oxotremorine-only group in the 48-hr retention test was significantly higher than the mean retention latencies of the groups that received co-infusion of telenzipine or methoctramine with the oxotremorine. These findings indicate that both muscarinic receptor types need to be activated in order for memory enhancement to occur.

James L. McGaugh School of Biological Sciences

Animals have evolved the amazing ability to store memory better for emotionally significant events. This ability depends on a convergence of hormonal and neurochemical signals in a small region of the medial temporal lobe of the brain called the basolateral amygdala (BLA). The neurotransmitter acetylcholine has been found to play a critical role in BLA modulation of memory storage via activation of muscarinic receptors. This project was the first analysis of the muscarinic receptor subtypes, which mediate this cholinergic activation of the BLA during consolidation. In collaboration with researchers from my laboratory, including Dr. Ann E. Power, who was directly responsible for guiding Anna’s research, Anna learned that cholinergic modulation of memory involves activation of both excitatory and inhibitory receptor systems in the BLA. These findings enhance our understanding of the neurobiological mechanisms of modulation of memory storage by emotion and arousal.