Neurotransmitters and Receptors in the Basal Ganglia
W. R. Wayne Martin in Functional Imaging in Movement Disorders, 2019
The caudate/putamen itself contains several different neuronal types. The most abundant neuron is the medium spiny neuron which is thought to use gamma-aminobutyric acid (GABA) as its neurotransmitter.23 These neurons comprise from 70 to 90% of the neurons within the caudate/putamen and often contain one or more of a number of neuropeptides in addition to GABA.5,6,8 The medium spiny neurons project to the major output regions of the basal ganglia, which are discussed below. They also have a large number of recurrent axon collaterals that are distributed primarily within the dendritic field of the neuron.25,26 In addition to the medium spiny neurons, there are also small numbers of large cholinergic interneurons (large aspiny neurons)27 and small somatostatin/neuropeptide Y interneurons (small aspiny neurons).28,29
Mitochondrial Dysfunction in Huntington Disease
Abhai Kumar, Debasis Bagchi in Antioxidants and Functional Foods for Neurodegenerative Disorders, 2021
HD is a dreadful neurodegenerative disease with characteristic cognitive behavioral features affecting 2.71 persons per 100,000 worldwide. The prevalence of HD can be as high as 15 persons per 100,000 which is observed in Western European population (Osellame, Blacker, and Duchen 2012; Dayalu and Albin 2015; Frank 2014; Sack 2010). Although HD is typically inherited, approximately 10% of the cases are due to a new mutation (Dayalu and Albin 2015). The disease is caused by an autosomal dominant mutation in huntingtin (HTT) gene (Milakovic and Johnson 2005). The pathogenesis of HD is initiated by neurodegeneration in the medium spiny neurons of striatum. Other parts of the brain, such as frontal and parietal cortices, are affected in the later stages of the disease (Sack 2010; Costa and Scorrano 2012). Gross pathology includes marked brain atrophy, which is more pronounced in the caudate nucleus and putamen, and large ventricular volumes (Sack 2010; Cepeda-Prado et al. 2012). In fact, positron emission tomography (PET) studies have shown changes in caudate, putamen, and cortex in both HD and presymptomatic HD individuals (Perez-De la Cruz and Carrillo-Mora 2010). The earliest signs of HD often are depression, mood changes, or psychosis. A suicidal tendency has also been noted in affected individuals. Poor attention and memory loss begin early and can progress slowly. The important recognizing feature is the involuntary and uncoordinated movement disorder accompanied by restlessness or “fidgeting.” The characteristics of chorea (Gk “dance”) become prominent over time (Sack 2010).
Abstinent Food Plans for Processed Food Addiction
Joan Ifland, Marianne T. Marcus, Harry G. Preuss in Processed Food Addiction: Foundations, Assessment, and Recovery, 2017
Three other craving pathways are also susceptible to Pavlovian conditioning in response to processed food cues. The opiate pathways encode positive responses to sugar and fat within ventral striatal medium spiny neurons (Kelley et al., 2002). Downregulated opioid pathways were found in a morbidly obese population (Karlsson et al., 2015). Davis and Loxton found heightened opiate responses to palatable foods (Davis & Loxton, 2014). Euphoric endorphins have been found to be released excessively in the nucleus accumbens in both people with alcoholism and in those with sweet preference as well as their children (Fortuna, 2010).
Efficiency of 123I-ioflupane SPECT as the marker of basal ganglia damage in acute methanol poisoning: 6-year prospective study
Published in Clinical Toxicology, 2021
Katerina Kotikova, David Zogala, Vaclav Ptacnik, Jiri Trnka, Karel Kupka, Manuela Vaneckova, Zdenek Seidl, Pavel Diblik, Jarmila Heissigerova, Tomas Navratil, Martin Komarc, Ivan Zak, Kamila Polakova, Hana Brozova, Sergey Zakharov
An association exists between striatal 123I-ioflupane uptake and both the number of dopaminergic neurons in the substantia nigra pars compacta and the functional state of those neuron’s axon terminals [48,49]. Outputs of the substantia nigra pars compacta are directed to the spines of dendrites of GABAergic medium spiny neurons in the striatum. Therefore, DaT SPECT, by evaluating the function of dopaminergic terminal axons, provides indirect information on the numbers of surviving GABAergic neurons in the putamen, especially within its posterior part, the caudal putamen, containing motor circuits where the reductions of dopamine transporters are most severe. Our data are in accordance with results of previous studies that revealed the selective vulnerability of the posterior putamen to hypoxic–ischemic brain injury, which researchers determined to be due to vascular and biochemical factors [50]. Further, we observed certain asymmetry in dopaminergic terminal function decrease with relatively lower indices for the SBR for the left striatum. It is interesting that Parkinsonian disease pathology occurs asymmetrically as well, and clinical motor symptoms manifest unilaterally in the early stages of the disease [51].
The effects of Alzheimer's disease related striatal pathologic changes on the fractional amplitude of low-frequency fluctuations
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
The basal ganglia, a subcortical nuclei, interconnected with the cerebral cortex, thalamus, and other brain areas, is associated with a variety of functions, such as control of voluntary motor movements, procedural learning, habit learning, eye movements, cognition and emotion. The main structures comprising the basal ganglia are the striatum, globus pallidus, substantia nigra, and subthalamic nucleus (STN). The striatum is the largest structure of the basal ganglia and mainly consists of Fast Spiking Interneurons (FSI) and Medium Spiny Neurons (MSN) including D1 and D2 type dopamine receptors (Bolam et al. 2000). The globus pallidus is divided into two functionally distinct parts, called the internal (GPi) and the external (GPe) segments. The substantia nigra is a midbrain gray matter portion of the basal ganglia that has two parts – the pars compacta (SNc) and the pars reticulata (SNr). GPi and SNr are often considered as a single structure due to their closely related inputs and outputs and similarities in cytology and function. SNr-GPi complex inhibits the thalamus (Plenz and Kitai 1998; Bolam et al. 2000; Samuelsson and Kotaleski 2007).
Dyskinesia and Parkinson’s disease: animal model, drug targets, and agents in preclinical testing
Published in Expert Opinion on Therapeutic Targets, 2022
Valentina Cesaroni, Fabio Blandini, Silvia Cerri
Two relatively distinct pathways convey signals from the striatum through the basal ganglia: the direct pathway, originating from GABAergic striatal medium spiny neurons expressing dopamine D1 receptors and projecting monosynaptically to globus pallidus pars interna (GPi)/substantia nigra pars reticulata (SNpr); and the indirect pathway, originating from GABAergic striatal medium spiny neurons expressing D2 receptors and influencing GPi/SNpr via the globus pallidus pars externa (GPe) and the subthalamic nucleus (STN). These two pathways have opposite net effects on thalamic target structures: excitation of the direct pathway causes activation of thalamic neurons, whereas excitation of the indirect pathway leads to inhibition of thalamic neurons. Findings in dopamine-depleted animals have shown that a major imbalance between the activity of the direct and indirect striatal pathways is probably responsible for dyskinetic movements induced by chronic L-DOPA administration. In particular, a reduction of firing rate and a modified patterns of discharge of internal pallidus neurons, associated with a decreased firing rate and irregular firing patterns of subthalamic neurons, have been observed in LID. Moreover, mechanisms such as the non-physiological stimulation of dopamine-deprived receptors and abnormal synaptic plasticity at corticostriatal synapses seem to be equally involved in LID pathophysiology [12].
Related Knowledge Centers
- Dopamine Receptor
- Gabaergic
- Inhibitory Postsynaptic Potential
- Phenotype
- Basal Ganglia
- Neuron
- Striatum
- D1-Like Receptor
- D2-Like Receptor
- Thalamus