{"title":"Quantifying harmony between direct and indirect pathways in the basal ganglia: healthy and Parkinsonian states","authors":"Sang-Yoon Kim, Woochang Lim","doi":"10.1007/s11571-024-10119-8","DOIUrl":null,"url":null,"abstract":"<p>The basal ganglia (BG) show a variety of functions for motor and cognition. There are two competitive pathways in the BG; direct pathway (DP) which facilitates movement and indirect pathway (IP) which suppresses movement. It is well known that diverse functions of the BG may be made through “balance” between DP and IP. But, to the best of our knowledge, so far no quantitative analysis for such balance was done. In this paper, as a first time, we introduce the competition degree <span>\\({{\\mathcal {C}}}_d\\)</span> between DP and IP. Then, by employing <span>\\({{\\mathcal {C}}}_d\\)</span>, we quantify their competitive harmony (i.e., competition and cooperative interplay), which could lead to improving our understanding of the traditional “balance” so clearly and quantitatively. We first consider the case of normal dopamine (DA) level of <span>\\(\\phi ^*=0.3\\)</span>. In the case of phasic cortical input (10 Hz), a healthy state with <span>\\({{\\mathcal {C}}}_d^* = 2.82\\)</span> (i.e., DP is 2.82 times stronger than IP) appears. In this case, normal movement occurs via harmony between DP and IP. Next, we consider the case of decreased DA level, <span>\\(\\phi = \\phi ^*(=0.3)~x_{DA}\\)</span> (<span>\\(1 > x_{DA} \\ge 0\\)</span>). With decreasing <span>\\(x_{DA}\\)</span> from 1, the competition degree <span>\\({{\\mathcal {C}}}_d\\)</span> between DP and IP decreases monotonically from <span>\\({{\\mathcal {C}}}_d^*\\)</span>, which results in appearance of a pathological Parkinsonian state with reduced <span>\\({{\\mathcal {C}}}_d\\)</span>. In this Parkinsonian state, strength of IP is much increased than that in the case of normal healthy state, leading to disharmony between DP and IP. Due to such break-up of harmony between DP and IP, impaired movement occurs. Finally, we also study treatment of the pathological Parkinsonian state via recovery of harmony between DP and IP.</p>","PeriodicalId":10500,"journal":{"name":"Cognitive Neurodynamics","volume":null,"pages":null},"PeriodicalIF":3.1000,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cognitive Neurodynamics","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1007/s11571-024-10119-8","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"NEUROSCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
The basal ganglia (BG) show a variety of functions for motor and cognition. There are two competitive pathways in the BG; direct pathway (DP) which facilitates movement and indirect pathway (IP) which suppresses movement. It is well known that diverse functions of the BG may be made through “balance” between DP and IP. But, to the best of our knowledge, so far no quantitative analysis for such balance was done. In this paper, as a first time, we introduce the competition degree \({{\mathcal {C}}}_d\) between DP and IP. Then, by employing \({{\mathcal {C}}}_d\), we quantify their competitive harmony (i.e., competition and cooperative interplay), which could lead to improving our understanding of the traditional “balance” so clearly and quantitatively. We first consider the case of normal dopamine (DA) level of \(\phi ^*=0.3\). In the case of phasic cortical input (10 Hz), a healthy state with \({{\mathcal {C}}}_d^* = 2.82\) (i.e., DP is 2.82 times stronger than IP) appears. In this case, normal movement occurs via harmony between DP and IP. Next, we consider the case of decreased DA level, \(\phi = \phi ^*(=0.3)~x_{DA}\) (\(1 > x_{DA} \ge 0\)). With decreasing \(x_{DA}\) from 1, the competition degree \({{\mathcal {C}}}_d\) between DP and IP decreases monotonically from \({{\mathcal {C}}}_d^*\), which results in appearance of a pathological Parkinsonian state with reduced \({{\mathcal {C}}}_d\). In this Parkinsonian state, strength of IP is much increased than that in the case of normal healthy state, leading to disharmony between DP and IP. Due to such break-up of harmony between DP and IP, impaired movement occurs. Finally, we also study treatment of the pathological Parkinsonian state via recovery of harmony between DP and IP.
期刊介绍:
Cognitive Neurodynamics provides a unique forum of communication and cooperation for scientists and engineers working in the field of cognitive neurodynamics, intelligent science and applications, bridging the gap between theory and application, without any preference for pure theoretical, experimental or computational models.
The emphasis is to publish original models of cognitive neurodynamics, novel computational theories and experimental results. In particular, intelligent science inspired by cognitive neuroscience and neurodynamics is also very welcome.
The scope of Cognitive Neurodynamics covers cognitive neuroscience, neural computation based on dynamics, computer science, intelligent science as well as their interdisciplinary applications in the natural and engineering sciences. Papers that are appropriate for non-specialist readers are encouraged.
1. There is no page limit for manuscripts submitted to Cognitive Neurodynamics. Research papers should clearly represent an important advance of especially broad interest to researchers and technologists in neuroscience, biophysics, BCI, neural computer and intelligent robotics.
2. Cognitive Neurodynamics also welcomes brief communications: short papers reporting results that are of genuinely broad interest but that for one reason and another do not make a sufficiently complete story to justify a full article publication. Brief Communications should consist of approximately four manuscript pages.
3. Cognitive Neurodynamics publishes review articles in which a specific field is reviewed through an exhaustive literature survey. There are no restrictions on the number of pages. Review articles are usually invited, but submitted reviews will also be considered.