Basal gangliaThe basal ganglia (BG), or basal nuclei, are a group of subcortical nuclei, of varied origin, in the brains of vertebrates. In humans, and some primates, there are some differences, mainly in the division of the globus pallidus into an external and internal region, and in the division of the striatum. The basal ganglia are situated at the base of the forebrain and top of the midbrain. Basal ganglia are strongly interconnected with the cerebral cortex, thalamus, and brainstem, as well as several other brain areas.
Bipolar disorderBipolar disorder, previously known as manic depression, is a mental disorder characterized by periods of depression and periods of abnormally elevated mood that each last from days to weeks. If the elevated mood is severe or associated with psychosis, it is called mania; if it is less severe, it is called hypomania. During mania, an individual behaves or feels abnormally energetic, happy or irritable, and they often make impulsive decisions with little regard for the consequences.
ConnectomicsConnectomics is the production and study of connectomes: comprehensive maps of connections within an organism's nervous system. More generally, it can be thought of as the study of neuronal wiring diagrams with a focus on how structural connectivity, individual synapses, cellular morphology, and cellular ultrastructure contribute to the make up of a network. The nervous system is a network made of billions of connections and these connections are responsible for our thoughts, emotions, actions, memories, function and dysfunction.
PsychosisPsychosis is a condition of the mind that results in difficulties determining what is real and what is not real. Symptoms may include delusions and hallucinations, among other features. Additional symptoms are incoherent speech and behavior that is inappropriate for a given situation. There may also be sleep problems, social withdrawal, lack of motivation, and difficulties carrying out daily activities. Psychosis can have serious adverse outcomes. As with many psychiatric phenomena, psychosis has several different causes.
Diffusion MRIDiffusion-weighted magnetic resonance imaging (DWI or DW-MRI) is the use of specific MRI sequences as well as software that generates images from the resulting data that uses the diffusion of water molecules to generate contrast in MR images. It allows the mapping of the diffusion process of molecules, mainly water, in biological tissues, in vivo and non-invasively. Molecular diffusion in tissues is not random, but reflects interactions with many obstacles, such as macromolecules, fibers, and membranes.
ConnectomeA connectome (kəˈnɛktoʊm) is a comprehensive map of neural connections in the brain, and may be thought of as its "wiring diagram". An organism's nervous system is made up of neurons which communicate through synapses. A connectome is constructed by tracing the neuron in a nervous system and mapping where neurons are connected through synapses. The significance of the connectome stems from the realization that the structure and function of the human brain are intricately linked, through multiple levels and modes of brain connectivity.
Outline of bipolar disorderThe following outline is provided as an overview of and topical guide to bipolar disorder: Bipolar disorder – mental disorder with cyclical periods of depression and periods of elevated mood. The elevated mood is significant and is known as mania, a severe elevation that can be accompanied by psychosis in some cases, or hypomania, a milder form of mania. During mania, an individual behaves or feels abnormally energetic, elated, or irritable. Individuals often make poorly thought out decisions with little regard to the consequences.
Default mode networkIn neuroscience, the default mode network (DMN), also known as the default network, default state network, or anatomically the medial frontoparietal network (M-FPN), is a large-scale brain network primarily composed of the dorsal medial prefrontal cortex, posterior cingulate cortex, precuneus and angular gyrus. It is best known for being active when a person is not focused on the outside world and the brain is at wakeful rest, such as during daydreaming and mind-wandering.
Basal ganglia diseaseBasal ganglia disease is a group of physical problems that occur when the group of nuclei in the brain known as the basal ganglia fail to properly suppress unwanted movements or to properly prime upper motor neuron circuits to initiate motor function. Research indicates that increased output of the basal ganglia inhibits thalamocortical projection neurons. Proper activation or deactivation of these neurons is an integral component for proper movement.
Large-scale brain networkLarge-scale brain networks (also known as intrinsic brain networks) are collections of widespread brain regions showing functional connectivity by statistical analysis of the fMRI BOLD signal or other recording methods such as EEG, PET and MEG. An emerging paradigm in neuroscience is that cognitive tasks are performed not by individual brain regions working in isolation but by networks consisting of several discrete brain regions that are said to be "functionally connected".
StriatumThe striatum, or corpus striatum (also called the striate nucleus), is a nucleus (a cluster of neurons) in the subcortical basal ganglia of the forebrain. The striatum is a critical component of the motor and reward systems; receives glutamatergic and dopaminergic inputs from different sources; and serves as the primary input to the rest of the basal ganglia. Functionally, the striatum coordinates multiple aspects of cognition, including both motor and action planning, decision-making, motivation, reinforcement, and reward perception.
Cortico-basal ganglia-thalamo-cortical loopThe cortico-basal ganglia-thalamo-cortical loop (CBGTC loop) is a system of neural circuits in the brain. The loop involves connections between the cortex, the basal ganglia, the thalamus, and back to the cortex. It is of particular relevance to hyperkinetic and hypokinetic movement disorders, such as Parkinson's disease and Huntington's disease, as well as to mental disorders of control, such as attention deficit hyperactivity disorder (ADHD), obsessive–compulsive disorder (OCD), and Tourette syndrome.
Stimulant psychosisStimulant psychosis is a mental disorder characterized by psychotic symptoms (such as hallucinations, paranoid ideation, delusions, disorganized thinking, grossly disorganized behaviour). It involves and typically occurs following an overdose or several day 'binge' on psychostimulants; however, one study reported occurrences at regularly prescribed doses in approximately 0.1% of individuals within the first several weeks after starting amphetamine or methylphenidate therapy.
NeuroplasticityNeuroplasticity, also known as neural plasticity, or brain plasticity, is the ability of neural networks in the brain to change through growth and reorganization. It is when the brain is rewired to function in some way that differs from how it previously functioned. These changes range from individual neuron pathways making new connections, to systematic adjustments like cortical remapping. Examples of neuroplasticity include circuit and network changes that result from learning a new ability, information acquisition, environmental influences, practice, and psychological stress.
Bipolar II disorderBipolar II disorder (BP-II) is a mood disorder on the bipolar spectrum, characterized by at least one episode of hypomania and at least one episode of major depression. Diagnosis for BP-II requires that the individual must never have experienced a full manic episode. Otherwise, one manic episode meets the criteria for bipolar I disorder (BP-I). Hypomania is a sustained state of elevated or irritable mood that is less severe than mania yet may still significantly affect the quality of life and result in permanent consequences including reckless spending, damaged relationships and poor judgment.
Reward systemThe reward system (the mesocorticolimbic circuit) is a group of neural structures responsible for incentive salience (i.e., "wanting"; desire or craving for a reward and motivation), associative learning (primarily positive reinforcement and classical conditioning), and positively-valenced emotions, particularly ones involving pleasure as a core component (e.g., joy, euphoria and ecstasy). Reward is the attractive and motivational property of a stimulus that induces appetitive behavior, also known as approach behavior, and consummatory behavior.
Substance-induced psychosisSubstance-induced psychosis (commonly known as toxic psychosis or drug-induced psychosis) is a form of psychosis that is attributed to substance use. It is a psychosis that results from the effects of chemicals or drugs. Various psychoactive substances have been implicated in causing or worsening psychosis in users. Psychosis Psychosis manifests as disorientation, visual hallucinations and/or haptic hallucinations. It is a state in which a person's mental capacity to recognize reality, communicate, and relate to others is impaired, thus interfering with the capacity to deal with life's demands.
ManiaMania, also known as manic syndrome, is a mental and behavioral disorder defined as a state of abnormally elevated arousal, affect, and energy level, or "a state of heightened overall activation with enhanced affective expression together with lability of affect." During a manic episode, an individual will experience rapidly changing emotions and moods, highly influenced by surrounding stimuli. Although mania is often conceived as a "mirror image" to depression, the heightened mood can be either euphoric or dysphoric.
Schizoaffective disorderSchizoaffective disorder (SZA, SZD) is a mental disorder characterized by abnormal thought processes and an unstable mood. This diagnosis requires symptoms of both schizophrenia (usually psychosis) and a mood disorder: either bipolar disorder or depression. The main criterion is the presence of psychotic symptoms for at least two weeks without any mood symptoms. Schizoaffective disorder can often be misdiagnosed when the correct diagnosis may be psychotic depression, bipolar I disorder, schizophreniform disorder, or schizophrenia.
Limbic systemThe limbic system, also known as the paleomammalian cortex, is a set of brain structures located on both sides of the thalamus, immediately beneath the medial temporal lobe of the cerebrum primarily in the forebrain. Its various components support a variety of functions including emotion, behavior, long-term memory, and olfaction. The limbic system is involved in lower order emotional processing of input from sensory systems and consists of the amygdala, mammillary bodies, stria medullaris, central gray and dorsal and ventral nuclei of Gudden.
