Banca de DEFESA: ANA LUIZA ALVES DIAS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANA LUIZA ALVES DIAS
DATE: 27/02/2023
TIME: 14:00
LOCAL: https://meet.google.com/joh-topd-kmn
TITLE:

Respiratory brain rhythms in the olfactory bulb and medial prefrontal cortex during anxiety

KEY WORDS:

respiratory rhythms, anxiety, prefrontal cortex, olfactory bulb

PAGES: 57
BIG AREA: Ciências Biológicas
AREA: Fisiologia
SUMMARY:

Anxiety is characterized as a state of perception of threats that can lead to danger. It is considered an evolutionarily adaptive behavior that results in different physiological changes. The emotional response evoked by anxiety causes activation of brain areas and temporal coordination of neuromodulation. Over the past 20 years, studies have shown that changes in the activity of the hippocampus, amygdala, and prefrontal cortex (PFC) would be related to fear and anxiety responses. The connections between these areas are thought to be coordinated by the theta oscillations (~ 6 - 12 Hz).  However, recent findings have shown that a larger network could be related to the modulation of anxiety, which would be orchestrated by the projections from the olfactory bulb (OB) to the PFC. Namely, both the OB and PFC exhibit neuronal oscillations that synchronize to the phase of the respiratory cycle and are named respiratory rhythms (RR) because of their co-variability in peak frequency with the breathing rate. These refer to actual LFP oscillations coupled with breathing and not the mechanical process of breathing itself. Lower LFP frequencies present themselves as a mechanism for long-range communication through the synchronization of cortical brain regions during different behavioral states, which could be the case of RR. In this work, we wanted to understand how the changes in the respiratory cycle could influence the appearance of these oscillations and how they could be related to the behavioral state during anxiety. For that, we recorded respiration through intranasal pressure and LFPs from the medial PFC (anterior cingulate, prelimbic and medial orbital), OB and parietal cortex of 7 male Wistar rats as they freely behaved in the elevated plus maze (EPM). We found that the respiratory rate changes depending on the behavioral state (anxious vs non-anxious) and locomotor activity. Furthermore, changes in the LFP power spectrum also depend on the behavioral state and reflect changes in respiratory activity. Finally, we observed RR in the same frequency range as theta during more anxious states. We hypothesize that the theta rhythm described in previous anxiety studies may have been confused with RR, and that this rhythm may coordinate long-range communication in the brain, being found both in the frontal brain and in more distant regions such as the parietal cortex.

COMMITTEE MEMBERS:
Presidente - 1721223 - ADRIANO BRETANHA LOPES TORT
Externo à Instituição - FLAVIO FREITAS BARBOSA - UFPB
Externo à Instituição - ROBSON SCHEFFER TEIXEIRA - UK