Landeira-Fernandez, J. | bioRxiv Science

bioRxiv2021

The impact of age and education on phonemic and semantic verbal fluency: Behavioral and fMRI correlates

The purpose of this study was to examine the impact of age and education on the neural and behavioral correlates of verbal fluency. Forty-eight healthy adult participants were included: high-educated young and elderly, low-educated young and elderly. Participants performed semantic and phonemic and a control task during fMRI scanning. The phonemic fluency data showed an education effect across age groups. As for the semantic fluency data, there was an education effect only in young participants. The second-level fMRI results showed, in phonemic fluency, a main effect of age in the left posterior cingulate, superior temporal gyrus (STG) and right caudate, whereas the main effect of education involved activation in the right semantic fluency, there were a main effect of age in the left paracentral lobule and posterior cingulate, a main effect of education in the left claustrum and an interaction in the right claustrum and STG and the hippocampus bilaterally.

neuroscience↗

bioRxiv2019

Participation of the rostral anterior cingulate cortex in defensive behavior induced by electrical stimulation of the dorsal periaqueductal gray and contextual fear conditioning

The rostral anterior cingulate cortex (rACC) is a critical brain structure related to defensive behavior. However, still unclear is whether the rACC also plays a role in defensive behavior induced by electrical stimulation of the dorsal periaqueductal gray (dPAG). In the present study, rats were implanted with electrodes into the dPAG to determine freezing and escape response thresholds after sham or bilateral electrolytic lesions of the rACC. The duration of freezing behavior that outlasted electrical stimulation of the dPAG was also measured. The next day, these animals were subjected to contextual fear conditioning using footshock as an unconditioned stimulus. Lesions of the rACC did not change aversive freezing and escape response thresholds but disrupted post-dPAG stimulation freezing. The lesions also disrupted defensive freezing behavior and analgesia in the formalin test in response to contextual cues previously associated with footshock. These results indicate that the rACC is involved in some but not all aspects of defensive behavior generated at the level of the dPAG. The rACC also appears to play an important role in contextual fear conditioning.

neuroscience↗