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
• 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
• receptory GABA-A - agonisté farmakologie   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
• 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
• receptory GABA-A - agonisté farmakologie   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

We studied the effects of GABA receptor agonists microinjections in medullary raphé on the mechanically induced tracheobronchial cough response in anesthetized, unparalyzed, spontaneously breathing cats. The results suggest that GABA-ergic inhibition significantly contributes to the regulation of cough reflex by action of both GABA(A) and GABA(B) receptors. The data are consistent with inhomogeneous occurrence of GABA-ergic neurons in medullary raphé and their different involvement in the cough reflex control. Cells within rostral nucleus raphéobscurus with dominant role of GABA(A) receptors and neurons of rostral nucleus raphépallidus and caudal nucleus raphémagnus with dominant role of GABA(B) receptors participate in regulation of cough expiratory efforts. These cough control elements are distinct from cough gating mechanism. GABA-ergic inhibition in the raphé caudal to obex had insignificant effect on cough. Contradictory findings for GABA, muscimol and baclofen administration in medullary raphé suggest involvement of coordinated activity of GABA on multiple receptors affecting raphé neurons and/or the local neuronal circuits in the raphé modulating cough motor drive.

• MeSH
• baklofen farmakologie   terapeutické užití   MeSH
• kašel farmakoterapie   patofyziologie   MeSH
• kočky MeSH
• medulla oblongata účinky léků   fyziologie   MeSH
• muscimol farmakologie   terapeutické užití   MeSH
• nuclei raphe účinky léků   fyziologie   MeSH
• receptory GABA-A - agonisté farmakologie   terapeutické užití   MeSH
• receptory GABA-A fyziologie   MeSH
• receptory GABA-B - agonisté farmakologie   terapeutické užití   MeSH
• receptory GABA-B fyziologie   MeSH
• reflex účinky léků   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• kočky MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Inhibitory circuits in the auditory brainstem undergo multiple postnatal changes that are both activity-dependent and activity-independent. We tested to see if the shift from GABA- to glycinergic transmission, which occurs in the rat medial nucleus of the trapezoid body (MNTB) around the onset of hearing, depends on sound-evoked neuronal activity. We prevented the activity by bilateral cochlear ablations in early postnatal rats and studied ionotropic GABA and glycine receptors in MNTB neurons after hearing onset. The removal of the cochlea decreased responses of GABAA and glycine receptors to exogenous agonists as well as the amplitudes of inhibitory postsynaptic currents. The reduction was accompanied by a decrease in the number of glycine receptor- or vesicular GABA transporter-immunopositive puncta. Furthermore, the ablations markedly affected the switch in presynaptic GABAA to glycine receptors. The increase in the expression of postsynaptic glycine receptors and the shift in inhibitory transmitters were not prevented. The results suggest that inhibitory transmission in the MNTB is subject to multiple developmental signals and support the idea that auditory experience plays a role in the maturation of the brainstem glycinergic circuits.

• MeSH
• ablace * MeSH
• corpus trapezoideum fyziologie   MeSH
• inhibiční postsynaptické potenciály fyziologie   MeSH
• kochlea patofyziologie   chirurgie   MeSH
• krysa rodu rattus MeSH
• nervový přenos * MeSH
• nervový útlum účinky léků   fyziologie   MeSH
• novorozená zvířata MeSH
• receptory GABA-A - agonisté farmakologie   MeSH
• receptory GABA-A fyziologie   MeSH
• receptory glycinu agonisté   metabolismus   fyziologie   MeSH
• sluchové kmenové evokované potenciály fyziologie   MeSH
• transportéry VIAAT metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The role of rodent hippocampus has been intensively studied in different cognitive tasks. However, its role in discrimination of objects remains controversial due to conflicting findings. We tested whether the number and type of features available for the identification of objects might affect the strategy (hippocampal-independent vs. hippocampal-dependent) that rats adopt to solve object discrimination tasks. We trained rats to discriminate 2D visual objects presented on a computer screen. The objects were defined either by their shape only or by multiple-features (a combination of filling pattern and brightness in addition to the shape). Our data showed that objects displayed as simple geometric shapes are not discriminated by trained rats after their hippocampi had been bilaterally inactivated by the GABAA-agonist muscimol. On the other hand, objects containing a specific combination of non-geometric features in addition to the shape are discriminated even without the hippocampus. Our results suggest that the involvement of the hippocampus in visual object discrimination depends on the abundance of object's features.

• MeSH
• chování zvířat účinky léků   fyziologie   MeSH
• diskriminační učení účinky léků   fyziologie   MeSH
• generalizace (psychologie) účinky léků   fyziologie   MeSH
• hipokampus účinky léků   fyziologie   MeSH
• krysa rodu rattus MeSH
• muscimol farmakologie   MeSH
• operantní podmiňování účinky léků   fyziologie   MeSH
• potkani Long-Evans MeSH
• receptory GABA-A - agonisté farmakologie   MeSH
• rozpoznávání obrazu účinky léků   fyziologie   MeSH
• vnímání tvaru 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

Although animals often learn and monitor the spatial properties of relevant moving objects such as conspecifics and predators to properly organize their own spatial behavior, the underlying brain substrate has received little attention and hence remains elusive. Because the anterior cingulate cortex (ACC) participates in conflict monitoring and effort-based decision making, and ACC neurons respond to objects in the environment, it may also play a role in the monitoring of moving cues and exerting the appropriate spatial response. We used a robot avoidance task in which a rat had to maintain at least a 25cm distance from a small programmable robot to avoid a foot shock. In successive sessions, we trained ten Long Evans male rats to avoid a fast-moving robot (4cm/s), a stationary robot, and a slow-moving robot (1cm/s). In each condition, the ACC was transiently inactivated by bilateral injections of muscimol in the penultimate session and a control saline injection was given in the last session. Compared to the corresponding saline session, ACC-inactivated rats received more shocks when tested in the fast-moving condition, but not in the stationary or slow robot conditions. Furthermore, ACC-inactivated rats less frequently responded to an approaching robot with appropriate escape responses although their response to shock stimuli remained preserved. Since we observed no effect on slow or stationary robot avoidance, we conclude that the ACC may exert cognitive efforts for monitoring dynamic updating of the position of an object, a role complementary to the dorsal hippocampus.

• MeSH
• cingulární gyrus účinky léků   fyziologie   MeSH
• krysa rodu rattus MeSH
• muscimol farmakologie   MeSH
• neurony účinky léků   fyziologie   MeSH
• podněty MeSH
• potkani Long-Evans MeSH
• pozornost účinky léků   fyziologie   MeSH
• prostorové chování účinky léků   fyziologie   MeSH
• reakční čas fyziologie   MeSH
• receptory GABA-A - agonisté farmakologie   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

• MeSH
• antikonvulziva farmakokinetika   MeSH
• anxiolytika farmakokinetika   MeSH
• barbituráty farmakokinetika   farmakologie   terapeutické užití   MeSH
• benzodiazepiny farmakokinetika   farmakologie   terapeutické užití   MeSH
• hypnotika a sedativa farmakokinetika   farmakologie   terapeutické užití   farmakokinetika   MeSH
• lidé MeSH
• receptory GABA-A - agonisté * farmakokinetika   farmakologie   terapeutické užití   MeSH
• receptory GABA-A účinky léků   MeSH
• Check Tag
• lidé MeSH

Potentiation of GABAergic inhibition is a mechanism of action of many antiepileptic drugs. The potential use of an agonist of GABAA receptors, muscimol, as an antiepileptic drug was studied in immature rats by assessing anticonvulsant activity and side effects on motor activities. Anticonvulsant action was tested in two models of seizures (pentetrazol-induced convulsions and cortical epileptic afterdischarges). Off target effect on motor performance was assessed in a battery of tests and in the open field in three age groups (12-, 18- and 25-day-old rats). Muscimol was administered in doses from 0.1 to 1mg/kg i.p. Only the 1 mg/kg dose exhibited marked anticonvulsant effect against pentetrazol-induced convulsions in 12- and 18-day-old rats, proconvulsant effect was observed in the second model in 18- and 25-day-old rats as prolongation of afterdischarges. Even the 0.5 mg/kg dose suppressed spontaneous locomotion and heavily compromised motor performance. The effect on motor activity was marked in the youngest group and decreased with age. Due to the low anticonvulsant potency and serious side effects, systemic administration of a competitive agonist of GABAA receptors in immature animals is not a promising strategy for new anticonvulsants.

• MeSH
• antikonvulziva farmakologie   MeSH
• elektroencefalografie MeSH
• epilepsie farmakoterapie   patofyziologie   MeSH
• modely nemocí na zvířatech MeSH
• mozek účinky léků   růst a vývoj   patofyziologie   MeSH
• muscimol farmakologie   MeSH
• neuropsychologické testy MeSH
• pátrací chování účinky léků   fyziologie   MeSH
• pentylentetrazol MeSH
• pohybová aktivita účinky léků   fyziologie   MeSH
• potkani Wistar MeSH
• receptory GABA-A - agonisté farmakologie   MeSH
• stupeň závažnosti nemoci MeSH
• věkové faktory MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• záchvaty farmakoterapie   patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH