Multi-unit recording from the prefrontal cortex with optogenetic stimulation of the locus coeruleus: unveiling neural mechanisms under an attention task

• Grant number: 12/21387-8
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: February 01, 2013
• End date: January 31, 2014
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: João Pereira Leite
• Grantee: Lézio Soares Bueno Júnior
• Supervisor: Bita Moghaddam
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Institution abroad: University of Pittsburgh (Pitt), United States
• Associated to the scholarship: 12/06123-4 - Hippocampal-prefrontal synaptic plasticity in awake rats: effects of thalamic stimulation during natural sleep and implications for memory consolidation, BP.PD

Abstract

The prefrontal cortex (PFC) regulates attention toward task-relevant stimuli, being sensitive to neurochemical contexts. However, the multi-unit dynamics behind such contexts remain poorly studied. In fact, PFC activity patterns during preparatory attention were detailed only recently, but without neuromodulation testing. A critical component of this modulation comes from the noradrenergic locus coeruleus (LC), whose phasic activity underlies optimum performance in learned tasks. Given that tonic, but not phasic, LC activity precedes sporadic mistakes by trained animals, a persistence of this tonic activity may disrupt PFC function, thereby impairing attention across trials. To test this hypothesis employing cutting-edge electrophysiology in vivo, we will use behaving rats for optogenetic stimulation of LC with multi-electrode recording from PFC. Adult rats will be trained within operant chambers containing three light-cued holes for instrumental nose poke and a reward hole in the opposite wall. Correct pokes into lit holes will be reinforced, and misses will be punished by blackout. Once trained, the rats will be implanted with an electrode array (PFC) and optic fiber (LC). After surgery recovery, PFC spikes and local field potentials (LFP) will be recorded during task performance. Trials with or without LC tonic stimulation will be presented randomly. Using Matlab, recordings from stimulated and non-stimulated trials will be separately promediated, and their spike-LFP patterns will be compared. Our data may clarify intricate PFC mechanisms under attention deficits, benefitting from optogenetic tools and multi-unit recording in behaving rats. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BUENO-JUNIOR, LEZIO S.; SIMON, NICHOLAS W.; WEGENER, MEREDYTH A.; MOGHADDAM, BITA. Repeated Nicotine Strengthens Gamma Oscillations in the Prefrontal Cortex and Improves Visual Attention. NEUROPSYCHOPHARMACOLOGY, v. 42, n. 8, p. 1590-1598, JUL 2017. (12/21387-8)