Dataset Information

Memory enhancement with event-related stimulation of the rostral intralaminar thalamic nuclei.

ABSTRACT: The rostral intralaminar thalamic nuclei (ILn) are organized to activate pathways originating in medial prefrontal cortex (mPF) that mediate memory-guided responding during alert, wakeful states. Previous studies have shown that rostral ILn or mPF lesions produce deficits in delayed matching to position (DMTP). Here, we manipulated rostral ILn activity in rats by microinjecting drugs or applying electrical current and examined effects on DMTP. Inhibiting activity with the GABA(A) agonist muscimol impaired DMTP. Decreasing GABA(A) tone with FG-7142 (N-methyl-beta-carboline-3-carboxamide) improved DMTP at low but not high doses. Orexin A, which depolarizes thalamocortical neurons locally within the ILn, improved DMTP, whereas the cholinergic agonist carbachol impaired performance at the highest dose tested. These drug effects were unaffected by partial mPF lesions in a subset of animals. Microinjection results are consistent with an inverted-U relationship between thalamic activity and DMTP. This relationship was confirmed by event-related electrical stimulation, which produced improvement at low stimulation currents and impairment at higher currents. Electrical stimulation affected DMTP when applied at the start of the memory delay or choice response, but not earlier when trials began or the sample lever was presented. Our results are consistent with evidence that the rostral ILn play a role in retrieval, carrying response-related information across brief memory delays and facilitating memory-guided responding. They also provide evidence that treatments stimulating rostral ILn activity may be an effective means to enhance working memory and related cognitive processes and thus to treat disorders that affect these functions.

SUBMITTER: Mair RG

PROVIDER: S-EPMC2630113 | biostudies-literature | 2008 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Memory enhancement with event-related stimulation of the rostral intralaminar thalamic nuclei.

Mair Robert G RG Hembrook Jacqueline R JR

The Journal of neuroscience : the official journal of the Society for Neuroscience 20081201 52

The rostral intralaminar thalamic nuclei (ILn) are organized to activate pathways originating in medial prefrontal cortex (mPF) that mediate memory-guided responding during alert, wakeful states. Previous studies have shown that rostral ILn or mPF lesions produce deficits in delayed matching to position (DMTP). Here, we manipulated rostral ILn activity in rats by microinjecting drugs or applying electrical current and examined effects on DMTP. Inhibiting activity with the GABA(A) agonist muscimo ...[more]

PMID: 19109510

Similar Datasets

Project description:OBJECTIVE:Deep brain stimulation (DBS) of the centromedian thalamic nucleus (CM) can be an alternative treatment option for intractable epilepsy patients. Since CM may be involved in widespread cortico-subcortical networks, identification of the cortical sub-networks specific to the target stimuli may provide further understanding on the underlying mechanisms of CM DBS. Several brain structures have distinguishing brain connections that may be related to the pivotal propagation and subsequent clinical effect of DBS. METHODS:To explore core structures and their connections relevant to CM DBS, we applied electroencephalogram (EEG) and diffusion tensor imaging (DTI) to 10 medically intractable patients - three generalized epilepsy (GE) and seven multifocal epilepsy (MFE) patients unsuitable for resective surgery. Spatiotemporal activation pattern was mapped from scalp EEG by delivering low-frequency stimuli (5 Hz). Structural connections between the CM and the cortical activation spots were assessed using DTI. RESULTS:We confirmed an average 72% seizure reduction after CM DBS and its clinical efficiency remained consistent during the observation period (mean 21 months). EEG data revealed sequential source propagation from the anterior cingulate, followed by the frontotemporal regions bilaterally. In addition, maximal activation was found in the left cingulate gyrus and the right medial frontal cortex during the right and left CM stimulation, respectively. From DTI data, we confirmed concrete structural connections between CM and those maximal activation spots identified from EEG data. CONCLUSION:These results suggest that the anterior cingulate can be a core cortical structure for the bilateral propagation of CM stimulation. Our DTI findings also indicate that the propagation of CM stimulation may rely upon integrity of structural connections between CM and these key cortical regions. Structures and their connections found in this study may be relevant in the interpretation of the clinical outcomes of CM DBS.

Dataset Information

Memory enhancement with event-related stimulation of the rostral intralaminar thalamic nuclei.

Publications

Memory enhancement with event-related stimulation of the rostral intralaminar thalamic nuclei.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets