Banca de QUALIFICAÇÃO: ANNA GABRIELY BARROSO DE SA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ANNA GABRIELY BARROSO DE SA
DATE: 16/02/2024
TIME: 09:00
LOCAL: https://meet.google.com/jfw-nkyj-awi
TITLE:

  Activation of the basal ganglia during vocal communication in a non-human primate

KEY WORDS:

marmoset, subcortical areas, vocalization, vocal learning

PAGES: 30
BIG AREA: Ciências Biológicas
AREA: Fisiologia
SUMMARY:

Flexible speech is one of the core aspects of human communication. Despite being considered uniquely human among primates, recent evidence shows that some non-human primates also have vocal plasticity. Marmosets (Callithrix jacchus), a New World monkey, exhibit exceptionally flexible vocalizations. Given the homologies between human and marmoset brains, investigating the neural correlates of vocal flexibility in marmosets leads to a deeper understanding of the origin of vocal flexibility in humans. Much of the literature on the neural basis of primate vocalization focuses on cortical areas, leaving fundamental gaps in our knowledge about the role of subcortical regions. Basal ganglia are related to the choice/initiation of actions, fine motor control, and learning of motor sequences; hence, it is likely to be relevant for vocal flexibility. Here, using histological data previously collected, we test the hypothesis that basal ganglia in marmosets activate during vocal communication. We use the expression of immediate-early gene egr-1 to map neural activation in basal ganglia in three marmoset groups (n = 2 per group). The first group did not vocalize during testing (C), the second group heard playback vocalizations but did not vocalize (H/O), and the third group heard playback calls and vocalized (H/V). Using stereological methods, we quantified the number of cells expressing erg-1 in the caudate nucleus (Cd) and putamen (Pu). We used Poisson regression, where the number of cells per counting area was the dependent variable, and the group, animal identity, brain hemisphere, and histological section were included as predictors. We observed significant differences among the groups for Cd and Pu (p < 0.001 for both areas). Using a posthoc analysis, we observed an increase in egr-1 expression in both areas in the H/O condition (Cd: μ ± ep, 193.33 ± 13.87 cells/mm2; Pu: 167.5 ± 14.67 cells/mm2) compared to the C condition (Cd: 110.52 ± 11.33 cells/mm2; Pu: 77.5 ± 9.35 cells/mm2; p < 0.001, Poisson regression with Bonferroni corrected p-value). We observed a further significant increase in egr-1 expression in the same areas in the H/V condition (Cd: 502.10 ± 24.55 cells/mm2; Pu: 715.55 ± 34.85 cells/mm2) compared to the H/O condition (p < 0.001,  Poisson regression with Bonferroni corrected p-value). To control for the possibility that the observed changes were not specific but rather generalized in the brain, we also compared the number of erg-1 expressing cells in the primary sensory (A3) and motor (A4) areas. We did not observe a statistically significant difference among the three conditions using Poisson regression as before (p > 0.05). We also quantified the amount of locomotion during the one hour preceding the experimental end-point to verify if the difference in movement could explain the observed difference between the groups. We did not observe a correlation between the amount of locomotion in each group and the difference in erg-1 expression. Our results indicate that basal ganglia activate during listening and production of vocalization independent of other brain areas and body movements, supporting our hypothesis. The relevance of basal ganglia in the vocal learning of songbirds, together with our current result in marmosets, supports the idea that understanding the basal ganglia might be relevant to understanding the evolution of vocal learning.

COMMITTEE MEMBERS:
Presidente - 3086031 - DANIEL YASUMASA TAKAHASHI
Interna - 1871878 - KERSTIN ERIKA SCHMIDT
Interno - 1660044 - SIDARTA TOLLENDAL GOMES RIBEIRO