Prefrontal cortex Dotaz Zobrazit nápovědu
Acta physiologica Scandinavica, ISSN 0302-2994 suppl. 514, 1983
58 s. : il. ; 24 cm
Negativní příznaky jsou považovány za nejvíce perzistující a zneschopňující komponentu schizofrenie. Jejich možnost ovlivnění antipsychotiky zůstává sporná. Repetitivní transkraniální magnetická stimulace (rTMS) představuje novou možnost ovlivnění negativních příznaků schizofrenie. Teoretické zdůvodnění účinnosti rTMS u negativních příznaků schizofrenie lze spatřovat ve skutečnosti, že vysokofrekvenční rTMS má aktivační vliv na neurony mozkové kůry. Negativní korelace mezi aktivitou frontálního kortexu a závažností negativních příznaků byla opakovaně prokázána. Dalším neméně významným faktem je ovlivnění uvolňování dopaminu mezolimbického a mezostriatálního mozkového systému vysokofrekvenční stimulací frontálního kortexu. Konzistentní literární údaje mapující danou tématiku v klinické praxi prakticky neexistují.
Negative symptoms are regarded as the most persistent and disabling component of schizophrenia. The possibility of influencing them by means of antipsychotics remains problematic. Repetitive transcranial magnetic simulation (rTMS) presents a new opportunity for influencing negative schizophrenic symptoms. A theoretical justification of the effect of rTMS on negative schizophrenic symptoms can be seen in the fact that high-frequency rTMS has an activating impact on cortex neurons. The negative correlation between activity of the frontal cortex and severity of negative symptoms has been proved repeatedly. Another important fact is that dopamine can be released in the mesolimbic and mesostriatal brain systems by high-frequency stimulation of the frontal cortex. There are hardly any consistent published data mapping the subject in clinical practice.
- MeSH
- depresivní poruchy terapie MeSH
- dopamin metabolismus MeSH
- elektromagnetické jevy metody statistika a číselné údaje trendy MeSH
- finanční podpora výzkumu jako téma MeSH
- lidé MeSH
- prefrontální mozková kůra fyziologie patofyziologie MeSH
- příznaky a symptomy MeSH
- schizofrenie komplikace parazitologie terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- srovnávací studie MeSH
- MeSH
- modely neurologické MeSH
- prefrontální mozková kůra fyziologie MeSH
- Publikační typ
- přehledy MeSH
1st ed. viii, 248 s., il.
- Konspekt
- Anatomie člověka a srovnávací anatomie
- NLK Obory
- neurologie
The prefrontal cortex is deputed to higher functions, such as behavior and personality. It includes three regions: ventromedial, orbitofrontal, and dorsolateral. Each of them has a function. Devising, programming, and planning are all conditions related to the dorsolateral cortex, also responsible for rational content and decision. Damage to this region results in apathetic syndrome, a condition that causes loss of interest, initiative, and attention, and in the most severe cases leads to a lethargic state. It is also known as a form of secondary depression, the so-called pseudo-depression syndrome, according to Karl Kleist or apathetic-abulic-akinetic syndrome, according to Alexander Luria. The prefrontal dorsolateral syndrome is responsible for the reduction or abolition of free will. Free will is an expression of individual freedom. It allows the human being to have and express own opinions as well as to respect those of others. Free will is related to moral sense, a binomial which directs the individual towards a proper social conduct. In this review, we describe the effects of the pseudo-depression syndrome on free will, of which we treat both the anatomical site and the social aspect.
BACKGROUND: Treating memory and cognitive deficits requires knowledge about anatomical sites and neural activities to be targeted with particular therapies. Emerging technologies for local brain stimulation offer attractive therapeutic options but need to be applied to target specific neural activities, at distinct times, and in specific brain regions that are critical for memory formation. METHODS: The areas that are critical for successful encoding of verbal memory as well as the underlying neural activities were determined directly in the human brain with intracranial electrophysiological recordings in epilepsy patients. We recorded a broad range of spectral activities across the cortex of 135 patients as they memorised word lists for subsequent free recall. FINDINGS: The greatest differences in the spectral power between encoding subsequently recalled and forgotten words were found in low theta frequency (3-5 Hz) activities of the left anterior prefrontal cortex. This subsequent memory effect was proportionally greater in the lower frequency bands and in the more anterior cortical regions. We found the peak of this memory signal in a distinct part of the prefrontal cortex at the junction between the Broca's area and the frontal pole. The memory effect in this confined area was significantly higher (Tukey-Kramer test, p<0.05) than in other anatomically distinct areas. INTERPRETATION: Our results suggest a focal hotspot of human verbal memory encoding located in the higher-order processing region of the prefrontal cortex, which presents a prospective target for modulating cognitive functions in the human patients. The memory effect provides an electrophysiological biomarker of low frequency neural activities, at distinct times of memory encoding, and in one hotspot location in the human brain. FUNDING: Open-access datasets were originally collected as part of a BRAIN Initiative project called Restoring Active Memory (RAM) funded by the Defence Advanced Research Project Agency (DARPA). CT, ML, MTK and this research were supported from the First Team grant of the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fund.
- MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mapování mozku MeSH
- mozek fyziologie MeSH
- paměť * fyziologie MeSH
- prefrontální mozková kůra * fyziologie MeSH
- rozpomínání fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Neural components enabling flexible cognition and behavior are well-established, and depend mostly on proper intercommunication within the prefrontal cortex (PFC) and striatum. However, dense projections from the ventral hippocampus (vHPC) alter the functioning of the medial PFC (mPFC). Dysfunctional hippocampo-prefrontal connectivity negatively affects the integrity of flexible cognition, especially in patients with schizophrenia. In this study, we aimed to test the role of the vHPC and mPFC in a place avoidance task on a rotating arena using two spatial flexibility task variants - reversal learning and set-shifting. To achieve this, we inactivated each of these structures in adult male Long-Evans rats by performing bilateral local muscimol (a GABAA receptor agonist) injections. A significantly disrupted performance was observed in reversal learning in the vHPC-inactivated, but not in the mPFC-inactivated rats. These results confirm the notion that the vHPC participates in some forms of behavioral flexibility, especially when spatial cues are needed. It seems, rather unexpectedly, that the mPFC is not taxed in these flexibility tasks on a rotating arena.
- MeSH
- agonisté receptorů GABA-A farmakologie MeSH
- hipokampus účinky léků fyziologie MeSH
- krysa rodu rattus MeSH
- muscimol farmakologie MeSH
- pozornost účinky léků fyziologie MeSH
- prefrontální mozková kůra účinky léků fyziologie MeSH
- prostorové vidění účinky léků fyziologie MeSH
- reverzní učení účinky léků fyziologie MeSH
- učení vyhýbat se účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Neural components enabling flexible cognition and behavior are well-established, and depend mostly on proper intercommunication within the prefrontal cortex (PFC) and striatum. However, dense projections from the ventral hippocampus (vHPC) alter the functioning of the medial PFC (mPFC). Dysfunctional hippocampo-prefrontal connectivity negatively affects the integrity of flexible cognition, especially in patients with schizophrenia. In this study, we aimed to test the role of the vHPC and mPFC in a place avoidance task on a rotating arena using two spatial flexibility task variants - reversal learning and set-shifting. To achieve this, we inactivated each of these structures in adult male Long-Evans rats by performing bilateral local muscimol (a GABAA receptor agonist) injections. A significantly disrupted performance was observed in reversal learning in the vHPC-inactivated, but not in the mPFC-inactivated rats. These results confirm the notion that the vHPC participates in some forms of behavioral flexibility, especially when spatial cues are needed. It seems, rather unexpectedly, that the mPFC is not taxed in these flexibility tasks on a rotating arena.
- MeSH
- agonisté receptorů GABA-A farmakologie MeSH
- hipokampus účinky léků fyziologie MeSH
- krysa rodu rattus MeSH
- muscimol farmakologie MeSH
- pozornost účinky léků fyziologie MeSH
- prefrontální mozková kůra účinky léků fyziologie MeSH
- prostorové vidění účinky léků fyziologie MeSH
- reverzní učení účinky léků fyziologie MeSH
- učení vyhýbat se účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
It is well known that communication between the medial prefrontal cortex (mPFC) and the ventral hippocampus (vHPC) is critical for various cognitive and behavioral functions. However, the exact role of these structures in spatial coordination remains to be clarified. Here we sought to determine the involvement of the mPFC and the vHPC in the spatial retrieval of a previously learned active place avoidance task in adult male Long-Evans rats, using a combination of unilateral and bilateral local muscimol inactivations. Moreover, we tested the role of the vHPC-mPFC pathway by performing combined ipsilateral and contralateral inactivations. Our results showed not only bilateral inactivations of either structure, but also the combined inactivations impaired the retrieval of spatial memory, whereas unilateral one-structure inactivations did not yield any effect. Remarkably, muscimol injections in combined groups exerted similar deficits, regardless of whether the inactivations were contralateral or ipsilateral. These findings confirm the importance of these structures in spatial cognition and emphasize the importance of the intact functioning of the vHPC-mPFC pathway.
