Acta physiologica Scandinavica, ISSN 0302-2994 suppl. 514, 1983
58 s. : il. ; 24 cm
1st ed. viii, 248 s., il.
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
- Depressive Disorder therapy MeSH
- Dopamine metabolism MeSH
- Electromagnetic Phenomena methods statistics & numerical data trends MeSH
- Research Support as Topic MeSH
- Humans MeSH
- Prefrontal Cortex physiology physiopathology MeSH
- Signs and Symptoms MeSH
- Schizophrenia complications parasitology therapy MeSH
- Check Tag
- Humans MeSH
- Publication type
- Comparative Study MeSH
The effects of food reward on circadian system function were investigated in the hypothalamic nuclei, prefrontal cortex and liver. Food rewards of small hedonic and caloric value were provided for 16 days 3 h after light phase onset to male Wistar rats. The daily pattern of locomotor activity was monitored. Gene expression profiling performed in the dorsomedial hypothalamus (DMH) and liver at the time of reward delivery indicated transcriptional factors egr1 and npas2 as possible mediators of food reward effects. Candidate genes were measured in the suprachiasmatic nuclei (SCN), DMH, arcuate nucleus (ARC), prefrontal cortex (PFC) and liver along with per2 expression. A daily pattern in glycemia and per2 expression in the SCN was emphasized by food reward. The expression of egr1 was rhythmic in the SCN, DMH, PFC and liver and food reward weakened or diminished this rhythm. The expression of npas2 was rhythmic in all tissues except for the PFC where food reward induced rhythm in npas2 expression. Food reward induced npas2 and egr1 expression in the DMH at the time of reward delivery. We suppose that the DMH and PFC participate in the adjustment of the circadian system to utilize food reward-induced input via egr1 and npas2 expression.
- MeSH
- Circadian Rhythm Signaling Peptides and Proteins biosynthesis genetics MeSH
- Circadian Rhythm physiology MeSH
- Gene Expression MeSH
- Rats MeSH
- Dorsomedial Hypothalamic Nucleus metabolism MeSH
- Reward * MeSH
- Rats, Wistar MeSH
- Food Deprivation physiology MeSH
- Prefrontal Cortex metabolism MeSH
- Early Growth Response Protein 1 biosynthesis genetics MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
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
- Humans MeSH
- Magnetic Resonance Imaging MeSH
- Brain Mapping MeSH
- Brain physiology MeSH
- Memory * physiology MeSH
- Prefrontal Cortex * physiology MeSH
- Mental Recall physiology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Neurons in anterior cingulate and prefrontal cortex (ACC/PFC) carry information about behaviorally relevant target stimuli. This information is believed to affect behavior by exerting a top-down attentional bias on stimulus selection. However, attention information may not necessarily be a biasing signal but could be a corollary signal that is not directly related to ongoing behavioral success, or it could reflect the monitoring of targets similar to an eligibility trace useful for later attentional adjustment. To test this suggestion we quantified how attention information relates to behavioral success in neurons recorded in multiple subfields in macaque ACC/PFC during a cued attention task. We found that attention cues activated three separable neuronal groups that encoded spatial attention information but were differently linked to behavioral success. A first group encoded attention targets on correct and error trials. This group spread across ACC/PFC and represented targets transiently after cue onset, irrespective of behavior. A second group encoded attention targets on correct trials only, closely predicting behavior. These neurons were not only prevalent in lateral prefrontal but also in anterior cingulate cortex. A third group encoded target locations only on error trials. This group was evident in ACC and PFC and was activated in error trials "as if" attention was shifted to the target location but without evidence for such behavior. These results show that only a portion of neuronaly available information about attention targets biases behavior. We speculate that additionally a unique neural subnetwork encodes counterfactual attention information.
- MeSH
- Action Potentials physiology MeSH
- Analysis of Variance MeSH
- Time Factors MeSH
- Gyrus Cinguli cytology MeSH
- Macaca mulatta MeSH
- Neurons classification physiology MeSH
- Cues MeSH
- Attention physiology MeSH
- Prefrontal Cortex cytology MeSH
- Reaction Time physiology MeSH
- Photic Stimulation MeSH
- Space Perception physiology MeSH
- Choice Behavior physiology MeSH
- Bias MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article 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.
- MeSH
- Hippocampus * MeSH
- Rats MeSH
- Muscimol pharmacology MeSH
- Rats, Long-Evans MeSH
- Prefrontal Cortex MeSH
- Spatial Memory * MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't 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.
- MeSH
- Hippocampus * MeSH
- Rats MeSH
- Muscimol pharmacology MeSH
- Rats, Long-Evans MeSH
- Prefrontal Cortex MeSH
- Spatial Memory * MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
