scholarly journals Neural correlates of vocal initiation in the VTA/SNc of juvenile male zebra finches

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shin Yanagihara ◽  
Maki Ikebuchi ◽  
Chihiro Mori ◽  
Ryosuke O. Tachibana ◽  
Kazuo Okanoya

AbstractInitiation and execution of complex learned vocalizations such as human speech and birdsong depend on multiple brain circuits. In songbirds, neurons in the motor cortices and basal ganglia circuitry exhibit preparatory activity before initiation of song, and that activity is thought to play an important role in successful song performance. However, it remains unknown where a start signal for song is represented in the brain and how such a signal would lead to appropriate vocal initiation. To test whether neurons in the midbrain ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) show activity related to song initiation, we carried out extracellular recordings of VTA/SNc single units in singing juvenile male zebra finches. We found that a subset of VTA/SNc units exhibit phasic activity precisely time-locked to the onset of the song bout, and that the activity occurred specifically at the beginning of song. These findings suggest that phasic activity in the VTA/SNc represents a start signal that triggers song vocalization.

Author(s):  
Mensura Altumbabic ◽  
Marc R. Del Bigio ◽  
Scott Sutherland

ABSTRACT:Background:Transtentorial herniation of large cerebral fragments is a rare phenomenon.Method:Case StudyResults:Examination of the brain of a 35-year-old male showed massive intracerebral hemorrhage resulting in displacement of basal ganglia components into the fourth ventricle.Conclusions:Sufficiently rapid intracerebral bleeding can dissect fragments of cerebrum and displace them long distances across the tentorial opening.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jing Guang ◽  
Halen Baker ◽  
Orilia Ben-Yishay Nizri ◽  
Shimon Firman ◽  
Uri Werner-Reiss ◽  
...  

AbstractDeep brain stimulation (DBS) is currently a standard procedure for advanced Parkinson’s disease. Many centers employ awake physiological navigation and stimulation assessment to optimize DBS localization and outcome. To enable DBS under sedation, asleep DBS, we characterized the cortico-basal ganglia neuronal network of two nonhuman primates under propofol, ketamine, and interleaved propofol-ketamine (IPK) sedation. Further, we compared these sedation states in the healthy and Parkinsonian condition to those of healthy sleep. Ketamine increases high-frequency power and synchronization while propofol increases low-frequency power and synchronization in polysomnography and neuronal activity recordings. Thus, ketamine does not mask the low-frequency oscillations used for physiological navigation toward the basal ganglia DBS targets. The brain spectral state under ketamine and propofol mimicked rapid eye movement (REM) and Non-REM (NREM) sleep activity, respectively, and the IPK protocol resembles the NREM-REM sleep cycle. These promising results are a meaningful step toward asleep DBS with nondistorted physiological navigation.


2020 ◽  
Author(s):  
Chantelle S. Lloyd ◽  
Andrew A. Nicholson ◽  
Maria Densmore ◽  
Jean Théberge ◽  
Richard W. J. Neufeld ◽  
...  

2014 ◽  
Vol 26 (2) ◽  
pp. 296-304 ◽  
Author(s):  
Erman Misirlisoy ◽  
Patrick Haggard

The capacity to inhibit a planned action gives human behavior its characteristic flexibility. How this mechanism operates and what factors influence a decision to act or not act remain relatively unexplored. We used EEG readiness potentials (RPs) to examine preparatory activity before each action of an ongoing sequence, in which one action was occasionally omitted. We compared RPs between sequences in which omissions were instructed by a rule (e.g., “omit every fourth action”) and sequences in which the participant themselves freely decided which action to omit. RP amplitude was reduced for actions that immediately preceded a voluntary omission but not a rule-based omission. We also used the regular temporal pattern of the action sequences to explore brain processes linked to omitting an action by time-locking EEG averages to the inferred time when an action would have occurred had it not been omitted. When omissions were instructed by a rule, there was a negative-going trend in the EEG, recalling the rising ramp of an RP. No such component was found for voluntary omissions. The results are consistent with a model in which spontaneously fluctuating activity in motor areas of the brain could bias “free” decisions to act or not.


2021 ◽  
Vol 11 (5) ◽  
pp. 535
Author(s):  
Davide Sattin ◽  
Francesca Giulia Magnani ◽  
Laura Bartesaghi ◽  
Milena Caputo ◽  
Andrea Veronica Fittipaldo ◽  
...  

The amount of knowledge on human consciousness has created a multitude of viewpoints and it is difficult to compare and synthesize all the recent scientific perspectives. Indeed, there are many definitions of consciousness and multiple approaches to study the neural correlates of consciousness (NCC). Therefore, the main aim of this article is to collect data on the various theories of consciousness published between 2007–2017 and to synthesize them to provide a general overview of this topic. To describe each theory, we developed a thematic grid called the dimensional model, which qualitatively and quantitatively analyzes how each article, related to one specific theory, debates/analyzes a specific issue. Among the 1130 articles assessed, 85 full texts were included in the prefinal step. Finally, this scoping review analyzed 68 articles that described 29 theories of consciousness. We found heterogeneous perspectives in the theories analyzed. Those with the highest grade of variability are as follows: subjectivity, NCC, and the consciousness/cognitive function. Among sub-cortical structures, thalamus, basal ganglia, and the hippocampus were the most indicated, whereas the cingulate, prefrontal, and temporal areas were the most reported for cortical ones also including the thalamo-cortical system. Moreover, we found several definitions of consciousness and 21 new sub-classifications.


2021 ◽  
pp. 1-11
Author(s):  
Francesca Biondo ◽  
Charlotte Nymberg Thunell ◽  
Bing Xu ◽  
Congying Chu ◽  
Tianye Jia ◽  
...  

Abstract Background Sex-related differences in psychopathology are known phenomena, with externalizing and internalizing symptoms typically more common in boys and girls, respectively. However, the neural correlates of these sex-by-psychopathology interactions are underinvestigated, particularly in adolescence. Methods Participants were 14 years of age and part of the IMAGEN study, a large (N = 1526) community-based sample. To test for sex-by-psychopathology interactions in structural grey matter volume (GMV), we used whole-brain, voxel-wise neuroimaging analyses based on robust non-parametric methods. Psychopathological symptom data were derived from the Strengths and Difficulties Questionnaire (SDQ). Results We found a sex-by-hyperactivity/inattention interaction in four brain clusters: right temporoparietal-opercular region (p < 0.01, Cohen's d = −0.24), bilateral anterior and mid-cingulum (p < 0.05, Cohen's d = −0.18), right cerebellum and fusiform (p < 0.05, Cohen's d = −0.20) and left frontal superior and middle gyri (p < 0.05, Cohen's d = −0.26). Higher symptoms of hyperactivity/inattention were associated with lower GMV in all four brain clusters in boys, and with higher GMV in the temporoparietal-opercular and cerebellar-fusiform clusters in girls. Conclusions Using a large, sex-balanced and community-based sample, our study lends support to the idea that externalizing symptoms of hyperactivity/inattention may be associated with different neural structures in male and female adolescents. The brain regions we report have been associated with a myriad of important cognitive functions, in particular, attention, cognitive and motor control, and timing, that are potentially relevant to understand the behavioural manifestations of hyperactive and inattentive symptoms. This study highlights the importance of considering sex in our efforts to uncover mechanisms underlying psychopathology during adolescence.


1995 ◽  
Vol 29 (3) ◽  
pp. 276-281 ◽  
Author(s):  
P. F. Wadsworth ◽  
H. B. Jones ◽  
J. B. Cavanagh

Whole coronal slices from 6 levels of the brain of 16 cynomolgus monkeys (8 control and 8 treated by daily gavage with a novel pharmaceutical agent for one year) were examined histologically. Mineralized bodies were identified only in coronal sections passing through the optic chiasma and mammillary bodies. Identical mineralized structures were present in the basal ganglia of both control and treated animals. The majority were seen in the globus pallidus, occasionally in the putamen and once in the nearby caudate nucleus. These structures were partially ferruginated and also partially calcified. They appeared to arise in relation to small vessels. They are part of the naturally occurring background pathology of several species of non-human primates and the incidence in this study (3/8 control and 5/8 treated) was approximately what might be expected from reports in the literature. Mineralized bodies of the basal ganglia of primates represent a spontaneous lesion with a characteristic distribution. They may cause confusion in interpretation of toxicological studies if their natural occurrence is not appreciated.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bob Jacobs ◽  
Heather Rally ◽  
Catherine Doyle ◽  
Lester O’Brien ◽  
Mackenzie Tennison ◽  
...  

Abstract The present review assesses the potential neural impact of impoverished, captive environments on large-brained mammals, with a focus on elephants and cetaceans. These species share several characteristics, including being large, wide-ranging, long-lived, cognitively sophisticated, highly social, and large-brained mammals. Although the impact of the captive environment on physical and behavioral health has been well-documented, relatively little attention has been paid to the brain itself. Here, we explore the potential neural consequences of living in captive environments, with a focus on three levels: (1) The effects of environmental impoverishment/enrichment on the brain, emphasizing the negative neural consequences of the captive/impoverished environment; (2) the neural consequences of stress on the brain, with an emphasis on corticolimbic structures; and (3) the neural underpinnings of stereotypies, often observed in captive animals, underscoring dysregulation of the basal ganglia and associated circuitry. To this end, we provide a substantive hypothesis about the negative impact of captivity on the brains of large mammals (e.g., cetaceans and elephants) and how these neural consequences are related to documented evidence for compromised physical and psychological well-being.


2021 ◽  
pp. practneurol-2021-002942
Author(s):  
Yue Hui Lau ◽  
Ahmad Shahir Mawardi ◽  
Norzaini Rose Zain ◽  
Shanthi Viswanathan

A 33-year-old man with a history of chronic toluene abuse through glue sniffing, developed tremors, cerebellar signs and cognitive decline. MR scan of the brain showed global cerebral and cerebellar atrophy with symmetrical T2-weighted hypointensities in the basal ganglia, thalami and midbrain. After stopping glue sniffing, his tremors, ataxia of gait, speech and cognition partially improved. Early recognition and intervention of toluene-induced leukodystrophy could prevent ongoing morbidity and premature mortality.


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