House of Mind

"Biology gives you a brain. Life turns it into a mind" - Jeffrey Eugenides

  • 27th May
    2011
  • 27
What is dopamine responsible for?

Asked by: Anonymous

Dopamine is implicated in many neural, cognitive and motor processes. 

Some of these include:

  • Detection of short-latency visual stimuli
  • Detection of novel/salient events and stimuli
  • Learning signal: indicates reward prediction error (discrepancy between expected outcome and actual outcome)
  • Modulation of direct/indirect motor pathways 
  • Goal-directed movement
  • Hedonic aspects of reward 
  • Reinforcing properties of drugs
  • Indirect modulation of other neurotransmitter systems
  • DA dysregulation implicated in mood disorders, psychiatric disorders and neurodegenerative diseases.
  • 28th December
    2010
  • 28
In relation to the last question, I’m posting this schematic drawing of the human brain showing regions vulnerable to alcoholism-related abnormalities.  Alcohol effects by brain area/region: Cerebral cortex: Disrupts thought processes, which may lead to poor judgment; blunts senses (ex. increases pain threshold); depresses inhibition (ex. more talkative/confident/social).  Limbic system (hippocampal regions): Memory loss and exaggerated emotions.  Cerebellum: Uncoordination of muscle movements (ex. loss of “fine-tuning” in motor skills).  Hypothalamus + pituitary gland: Alcohol depresses nerve centers in the brain related to sexual arousal and performance. Sexual desire increases, but sexual function is decreased with excessive alcohol consumption. Alcohol also inhibits pituitary secretion of ADH (anti-diuretic hormone) so alcohol affects urine production and excretion.  Medulla: Because the medulla controls what some consider automatic functions (i.e. heart rate, temperature, breathing), alcohol consumption may cause sleepiness. Increased or excessive consumption may lead to unconsciousness.  Taken from How Alcohol Affects the Brain Additional ones:  Frontal lobe: Alcohol diminishes inhibition and impairs executive function. Drunks make worse decisions because critical brain areas involved in planning, evaluating risk, and analysis are affected.  Temporal lobe: Critical brain area for understanding/comprehension. Impaired by alcohol.  Parietal lobe: Visuo-spatial orientation and sensorimotor cortices.  Occipital lobe: Visual processing.  Corpus callosum: Connects right and left cerebral hemispheres and facilitates communication between hemispheres.  Thalamus: Main relay center of the brain. The thalamus relays sensory, motor, spatial signals, among others, to cortical areas of the brain. Basically, almost every input that we receive passes through the thalamus at one point or another.  Now you know what these do, now imagine the toll excessive drinking may have on these structures and their function….

In relation to the last question, I’m posting this schematic drawing of the human brain showing regions vulnerable to alcoholism-related abnormalities. 

Alcohol effects by brain area/region:

  • Cerebral cortex: Disrupts thought processes, which may lead to poor judgment; blunts senses (ex. increases pain threshold); depresses inhibition (ex. more talkative/confident/social). 
  • Limbic system (hippocampal regions): Memory loss and exaggerated emotions. 
  • Cerebellum: Uncoordination of muscle movements (ex. loss of “fine-tuning” in motor skills). 
  • Hypothalamus + pituitary gland: Alcohol depresses nerve centers in the brain related to sexual arousal and performance. Sexual desire increases, but sexual function is decreased with excessive alcohol consumption. Alcohol also inhibits pituitary secretion of ADH (anti-diuretic hormone) so alcohol affects urine production and excretion. 
  • Medulla: Because the medulla controls what some consider automatic functions (i.e. heart rate, temperature, breathing), alcohol consumption may cause sleepiness. Increased or excessive consumption may lead to unconsciousness. 

Taken from How Alcohol Affects the Brain

Additional ones: 

Frontal lobe: Alcohol diminishes inhibition and impairs executive function. Drunks make worse decisions because critical brain areas involved in planning, evaluating risk, and analysis are affected. 

Temporal lobe: Critical brain area for understanding/comprehension. Impaired by alcohol. 

Parietal lobe: Visuo-spatial orientation and sensorimotor cortices. 

Occipital lobe: Visual processing. 

Corpus callosum: Connects right and left cerebral hemispheres and facilitates communication between hemispheres. 

Thalamus: Main relay center of the brain. The thalamus relays sensory, motor, spatial signals, among others, to cortical areas of the brain. Basically, almost every input that we receive passes through the thalamus at one point or another. 

Now you know what these do, now imagine the toll excessive drinking may have on these structures and their function….

  • 26th March
    2010
  • 26
Fig. 7 Forebrain Processes in Normal Dreaming- An Integration of Neuropsychological, Neurophysiological and Neuroimaging Data Also helpful for identifying some brain structure organization and function Source: Hobson, JA, Pace-Schott, EF. 2002. The cognitive neuroscience of sleep: neuronal systems, consciousness and learning. Nature Reviews Neuroscience. 3: 679-693. doi:10.1038/nrn915 

Fig. 7 Forebrain Processes in Normal Dreaming- An Integration of Neuropsychological, Neurophysiological and Neuroimaging Data

Also helpful for identifying some brain structure organization and function

Source: Hobson, JA, Pace-Schott, EF. 2002. The cognitive neuroscience of sleep: neuronal systems, consciousness and learning. Nature Reviews Neuroscience. 3: 679-693. doi:10.1038/nrn915 

  • 23rd March
    2010
  • 23