User:Ephlegar/sandbox
IMPORTANT: So as not to have to "double edit," this sandbox is not identical to the caudate nucleus stub.
Neurochemistry
[edit]The VTA is located in the midbrain at the top of the brainstem. Due to its role in dopamine synthesis, the VTA is often designated as one of the "pleasure centers" of the brain. [1] The SNc is located in the midbrain and contains cell projections to the caudate and putamen, utilizing the neurotransmitter dopamine. [2]
Motor Functions
[edit]Spatial Mnemonic Processing
[edit]The caudate nucleus integrates spatial information with motor behavior formulation. Selective impairment of spatial working memory in subjects with Parkinson’s disease and the knowledge of the disease’s impact on the amount of dopamine supplied to the striatum have linked the caudate nucleus to spatial and nonspatial mnemonic processing. Spatially dependent motor preparation has been linked to the caudate nucleus through event-related fMRI analysis techniques. Activity in the caudate nucleus was demonstrated to be greater during tasks featuring spatial and motoric memory demands than those that involved nonspatial tasks.[3] Specifically, spatial working memory activity has been observed, via fMRI studies of delayed recognition, to be greater in the caudate nucleus when the activity immediately preceded a motor response. These results indicate that the caudate nucleus could be involved in coding a motor response. With this in mind, the caudate nucleus could be involved in the recruitment of the motor system to support working memory performance by the mediation of sensory-motor transformations. [4]
Directed Movements
[edit]The caudate nucleus contributes importantly to body and limbs posture and the speed and accuracy of directed movements. Deficits in posture and accuracy during paw usage tasks were observed following the removal of caudate nuclei in felines. A delay in initiating performance and the need to constantly shift body position were both observed in cats following partial removal of the nuclei. [5]
Following the application of cocaine to the caudate nucleus and the resulting lesions produced, a “leaping or forward movement” was observed in monkeys. Due to its association with damage to the caudate, this movement demonstrates the inhibitory nature of the caudate nucleus. The “motor release” observed as a result of this procedure indicates that the caudate nucleus inhibits the tendency for an animal to move forward without resistance. [6]
Cognitive Functions
[edit]Memory
[edit]The dorsal-prefrontal cortex subcortical loop involving the caudate nucleus has been linked to deficits in working memory, specifically in schizophrenic patients. Functional imaging has shown activation of this subcortical loop during working memory tasks in primates and healthy human subjects. The caudate may be affiliated with deficits involving working memory from before illness onset as well. A larger caudate nucleus volume has been associated with increased errors on spatial working memory tasks. [7]
The amygdala sends direct projections to the caudate nucleus. Both the amygdala and the caudate nucleus have direct and indirect projections to the hippocampus. The influence of the amygdala on memory processing in the caudate nucleus has been demonstrated with the finding that lesions involving the connections between these two structures “block the memory-enhancing effects of oxotremorine infused into the caudate nucleus". In a study involving rats given water-maze training, the caudate nucleus was discovered to enhance memory of visually cued training after amphetamine was infused post-training into the caudate. [8]
Sleep
[edit]Bilateral lesions in the head of the caudate nucleus in cats were correlated with a decrease in the duration of deep slow wave sleep during the sleep-wakefulness cycle. With a decrease in total volume of deep slow wave sleep, the transition of short-term memory to long-term memory may also be affected negatively. [9] However, the effects of caudate nuclei removal on the sleep-wakefulness pattern of cats have not been permanent. Normalization has been discovered after a period of three months following caudate nuclei ablation. This discovery could be due to the inter-related nature of the roles of the caudate nucleus and the frontal cortex in controlling levels of central nervous system activation. The cats with caudate removal, although permanently hyperactive, had a significant decrease in rapid eye movement sleep (REMS) time that only lasted for about two months. However, afrontal cats had a permanent decrease in REMS time and only a temporary period of hyperactivity. [10]
Contrasting with associations between “deep”, REM sleep and the caudate nucleus, a study involving EEG and fMRI measures during human sleep cycles has indicated that the caudate nucleus demonstrates reduced activity during non-REM sleep across all sleep stages. [11] Additionally, studies of human caudate nuclei volume in congenital central hyperventilation syndrome (CCHS) subjects established a correlation between CCHS and a significant reduction in left and right caudate volume. CCHS is a genetic disorder that affects the sleep cycle due to a reduced drive to breathe. Therefore, the caudate nucleus has been proven to play a role in human sleep cycles. [12]
Emotion
[edit]Approach-attachment behavior and affect are also controlled by the caudate nucleus. Cats with bilateral removal of the caudate nuclei persistently approached and followed objects, attempting to contact the target, while exhibiting a friendly disposition by the elicitation of treading of the forelimbs and purring. The magnitude of the behavioral responses was correlated to the extent of the removal of the nuclei. Reports of human patients with selective damage to the caudate nucleus show unilateral caudate damage resulting in loss of drive, obsessive-compulsive disorder, stimulus-bound perseverance related behavior, and hyperactivity. Most of these deficits can be classified as relating to approach-attachment behaviors, from approaching a target to romantic love. [13]
Language
[edit]Local shape deformations of the medial surface of the caudate have been correlated with verbal learning capacity for females and the number of perseverance errors on spatial and verbal fluency working memory tasks for males. Specifically, a larger caudate nucleus volume has been linked with better verbal fluency performance. [14]
References
[edit]- ^ "The Pleasure Centres Affected By Drugs". Retrieved 5 December 2013.
- ^ McDougal, David. "Substantia Nigra". Retrieved 5 December 2013.
- ^ Postle, Bradley (23). "Dissociation of human caudate nucleus activity in spatial and nonspatial working memory: An event-related fmri study". Cognitive Brain Research. 8 (2): 107–115. doi:10.1016/S0926-6410(99)00010-5. PMID 10407200.
{{cite journal}}: Check date values in:|date=and|year=/|date=mismatch (help); Unknown parameter|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help) - ^ Postle, Bradley (18). "Spatial working memory activity of the caudate nucleus is sensitive to frame of reference". Cognitive, Affective, & Behavioral Neuroscience. 3 (2): 133–144. doi:10.3758/CABN.3.2.133. PMID 12943328. S2CID 26888.
{{cite journal}}: Check date values in:|date=and|year=/|date=mismatch (help); Unknown parameter|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help) - ^ Villablanca, Jaime (2010). "Why do we have a caudate nucleus?". Acta Neurobiologiae Experimentalis. 70 (1): 95–105. PMID 20407491.
- ^ White, Norman (12). "Some highlights of research on the effects of caudate nucleus lesions over the past 200 years". Behavioural Brain Research. 199 (1): 3–23. doi:10.1016/j.bbr.2008.12.003. PMID 19111791. S2CID 3717092. Retrieved 19 November 2013.
{{cite journal}}: Check date values in:|date=and|year=/|date=mismatch (help); Unknown parameter|month=ignored (help) - ^ Hannan, Katrina (11). "Caudate nucleus volume in individuals at ultra-high risk of psychosis: A cross-sectional magnetic resonance imaging study". Psychiatry Research: Neuroimaging. 182 (3): 223–230. doi:10.1016/j.pscychresns.2010.02.006. PMID 20488675. S2CID 35678217.
{{cite journal}}: Check date values in:|date=and|year=/|date=mismatch (help); Unknown parameter|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help) - ^ McGaugh, James (2004). "The Amygdala Modulates The consolidation of memories of emotionally arousing experiences". Annual Rev. Neurosci. 27: 1–28. doi:10.1146/annurev.neuro.27.070203.144157. PMID 15217324. Retrieved 19 November 2013.
- ^ Gogichadze, M. (2009). "Sleep disorders and disturbances in memory processing related to the lesion of the caudate nucleus". Parkinsonism and Related Disorders: S167–S168. doi:10.1016/S1353-8020(09)70639-X.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Villablanca, Jaime (1). "Counterpointing the functional role of the forebrain and of the brainstem in the control of the sleep-waking system". Journal of Sleep Research. 13 (3): 179–208. doi:10.1111/j.1365-2869.2004.00412.x. PMID 15339255. S2CID 44550700. Retrieved 19 November 2013.
{{cite journal}}: Check date values in:|date=and|year=/|date=mismatch (help); Unknown parameter|month=ignored (help) - ^ Kaufmann, C (March 2006). "Brain activation and hypothalamic functional connectivity during human non-rapid eye movement sleep: an EEG/fMRI study". Brain. 129 (3): 655–667. doi:10.1093/brain/awh686. PMID 16339798. Retrieved 19 November 2013.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help)CS1 maint: date and year (link) - ^ Kumar, R (10). "Reduced caudate nuclei volumes in patients with congenital central hypoventilation syndrome". Neuroscience. 163 (4): 1373–1379. doi:10.1016/j.neuroscience.2009.07.038. PMC 2761724. PMID 19632307.
{{cite journal}}: Check date values in:|date=and|year=/|date=mismatch (help); Unknown parameter|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help) - ^ Villablanca, Jaime (2010). "Why do we have a caudate nucleus?". Acta Neurobiologiae Experimentalis. 70 (1): 95–105. PMID 20407491.
- ^ Hannan, Katrina (11). "Caudate nucleus volume in individuals at ultra-high risk of psychosis: A cross-sectional magnetic resonance imaging study". Psychiatry Research: Neuroimaging. 182 (3): 223–230. doi:10.1016/j.pscychresns.2010.02.006. PMID 20488675. S2CID 35678217.
{{cite journal}}: Check date values in:|date=and|year=/|date=mismatch (help); Unknown parameter|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help)