Interindividual differences in memory system local field potential activity predict behavioral strategy on a dual-solution T-maze.

Individuals can use diverse behavioral strategies to navigate their environment including hippocampal-dependent place strategies reliant upon cognitive maps and striatal-dependent response strategies reliant upon egocentric body turns. The existence of multiple memory systems appears to facilitate successful navigation across a wide range of environmental and physiological conditions. The mechanisms by which these systems interact to ultimately generate a unitary behavioral response, however, remain unclear. We trained 20 male, Sprague-Dawley rats on a dual-solution T-maze while simultaneously recording local field potentials that were targeted to the dorsolateral striatum and dorsal hippocampus. Eight rats spontaneously exhibited a place strategy while the remaining 12 rats exhibited a response strategy. Interindividual differences in behavioral strategy were associated with distinct patterns of LFP activity between the dorsolateral striatum and dorsal hippocampus. Specifically, striatal-hippocampal theta activity was in-phase in response rats and out-of-phase in place rats and response rats exhibited elevated striatal-hippocampal coherence across a wide range of frequency bands. These contrasting striatal-hippocampal activity regimes were (a) present during both maze-learning and a 30 min premaze habituation period and (b) could be used to train support vector machines to reliably predict behavioral strategy. Distinct patterns of neuronal activity across multiple memory systems, therefore, appear to bias behavioral strategy selection and thereby contribute to interindividual differences in behavior.

Global Neurosurgery Education in United States Residency Programs.

BACKGROUND: Global neurosurgery encompasses the social and surgical practices that effect the neurologic health of vulnerable and underserved populations in domestic and international resource-limited settings. Formal academic engagement in global neurosurgery is limited in residency programs. Here we explore the current status of global neurosurgery education in residency programs across the United States. METHODS: We contacted 115 Accreditation Council for Graduate Medical Education-accredited residency programs in the United States to complete an 8-question electronic survey on global neurosurgery education. Questions were framed with binary "yes" or "no" answers to indicate presence of a global health activity. Respondents provided additional information if desired. Global education activity was categorized based on the number of resources attributed to global health activities: low (0-2), moderate (3-5), or high (6-8). RESULTS: Thirty-four residency programs completed the survey (29.6%). The majority of respondents reported offering funding for research and educational opportunities in global neurosurgery (n = 22). Programs tended to support global neurosurgery conferences (n = 20), periodic dedicated lectures (n = 15), and rotations in resource-constrained or marginalized communities domestically or abroad (n = 15). Some programs offer continuity clinics in marginalized settings (n = 10), supplementary reading material (n = 8), core curricula (n = 6), or a designated residency track in global neurosurgery (n = 3). The majority of residency programs had low-level engagement in global neurosurgery (n = 18), with only 3 programs having high levels of engagement. CONCLUSIONS: Formal global neurosurgery training is limited within US residency programs. With rising trends in the neurosurgical disease burden globally, it may benefit residency programs to develop training paths to equip the next generation of neurosurgeons to address such needs.