@phdthesis{oai:oist.repo.nii.ac.jp:00001322,
 author = {Sieveritz, Bianca},
 month = {2021-05-31, 2020-03-24},
 note = {Decision-making is impaired in Parkinsonian patients. One brain area that shows disrupted activity in Parkinson's disease are the ventral motor thalamic nuclei. Input from the ventral motor thalamic nuclei to prelimbic cortical layer 1 may excite and inhibit corticostriatal neurons in deeper layers of prelimbic cortex. Prelimbic corticostriatal neurons are important in cost-benefit decision-making. Hence, ventral motor thalamic input to prelimbic cortex may also be involved in cost-benefit decision-making and disruption of their activity in Parkinsonian patients may play a crucial role in impaired decision-making. This thesis addresses the first of these two hypotheses. In particular, I aimed to (1) investigate the innervation pattern of ventromedial projections to prelimbic cortical layer 1, and (2) to determine whether optogenetic inhibition of ventral motor thalamic axon terminals in prelimbic cortical layer 1 changes choice behavior of rats on a cost-benefit decision-making paradigm.
A combination of anterograde tracing, immunohistochemistry and light microscopy revealed that ventromedial thalamic axon terminals in prelimbic cortical layer 1 make contacts onto dendrites of pyramidal neurons, corticostriatal neurons and layer 1 inhibitory interneurons. Systematic random sampling further indicated that the majority of contacts onto dendritic tufts of pyramidal neurons are made on those of corticostriatal neurons, and that layer 1 inhibitory interneurons receive less input from ventral motor thalamic nuclei than pyramidal neurons.
Optogenetic inhibition of ventral motor thalamic axon terminals in prelimbic cortical layer 1 significantly changed choice behavior of rats on a cost-benefit decision-making paradigm. Sprague-Dawley rats were offered a choice between a high benefit-high cost and a low benefit-low cost option. Optogenetic inhibition induced a bias towards the high benefit-high cost option, even though the perception of benefit and cost values of animals remained unchanged.
The results indicate that ventral motor thalamic nuclei are critical in cost-benefit decision-making and that they may modulate the activity of prelimbic pyramidal neurons on this paradigm. The idea that ventral motor thalamic nuclei are primarily involved in motor control must be reevaluated and their potential role in choice behavior should be explored further in future studies.},
 school = {Okinawa Institute of Science and Technology Graduate University},
 title = {コスト・ベネフィット比較に基づく意思決定における腹側視床－辺縁前皮質投射神経に関する研究},
 year = {}
}