lect fin fall 2020

basal-ganglia.md

@@ -1,5 +1,6 @@
 ## Modulation of movement by the basal ganglia
 
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 <div></div>
 
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 </div>
 
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+<div style="font-size:0.5em;"> 
+<!-- date: -->
+</div>
+
 Note:
 
 * Modulate the initiation, termination, amplitude, and selection of movement
 
 * But basal ganglia also has varied non-motor roles:
-  - also with the non-motor loops (limbic system class):  
+  - also with "non-motor" circuits (limbic system class):  
   - involved in learning, reward mechanisms
       * Response-outcome associations
       * Stimulus-response associations
   - and also non-motor prefrontal cortex loops to help in selection of conscious goals, decisions
 
-[http://www.youtube.com/watch?v=Td4QGHNJ8Q0](http://www.youtube.com/watch?v=Td4QGHNJ8Q0)
+
+modulate (wordnet, verb)  
+: vary the frequency, amplitude, phase, or other characteristic of (electromagnetic waves)  
+: adjust the pitch, tone, or volume of  
+: regulate  
 
 
 --
@@ -51,20 +61,23 @@ Note:
 
 We will discuss…
 
-* Basal Ganglia components
-* Other disinhibition loops
+* basal ganglia components
+* inhibiting inhibition, "disinhibition" loops
+* relevant neurotransmitter receptor signaling systems
 
 ---
 
 ## Corpus striatum
 
-* Corpus striatum ('striped body') contains two nuclei– the caudate and putamen
+* Corpus striatum ('striped body') contains two portions– the caudate and putamen
 * Function as the input zones for the basal ganglia
 * Most regions of the cortex project to the striatum. Prominent innervation from the associational cortical areas of the frontal and parietal lobes. Collectively called the corticostriatal pathway
-* Neurons in striatum that receive corticostriatal input are called medium spiny neurons. Large dendritic trees, integrate information form a variety of structures
+* Neurons in striatum that receive corticostriatal input are called **medium spiny neurons**. Large dendritic trees, integrate information from a variety of structures
 
 Note:
 
+Caudate and putamen separated by white matter (internal capsule) in mid to caudal coronal view sections of the brain
+
 
 --
 
@@ -76,6 +89,7 @@ Most cortical areas project to the striatum, except for primary auditory cortex
 
 Note:
 
+Axonal input to the striatum originates from all over the cortex, but with little input from the primary sensory areas of visual and auditory cortex  
 
 ---
 
@@ -98,6 +112,12 @@ basal forebrain nuclei
 : roles in attention, wakefulness, REM sleep  
 
 
+fornix  
+: latin for "arch"  
+: output of hippocampus  
+: hippocampal commissure in mid region  
+: mammillary body at one end of this tract  
+
 ---
 
 ## Anatomy of the basal ganglia: caudate and putamen
@@ -254,8 +274,9 @@ Note:
 
 Recall that the superior colliculus contains upper motor neurons concerned with eye movements
 
-[http://www.youtube.com/watch?v=P6uTlnyNaTs](http://www.youtube.com/watch?v=P6uTlnyNaTs)
+Record spikes with microelectrodes inserted into caudate and SNr and superior colliculus. 
 
+Count spikes surrounding eye movement period, y axis is count (histogram), x axis is time (100s of msec to sec)
 
 ---
 
@@ -266,7 +287,7 @@ Recall that the superior colliculus contains upper motor neurons concerned with
 
 Note:
 
-Overall excitatory by disinhibiting the upper motor neurons in the cortex (promotes movement, initiation of motor commands)
+Overall effect of direct pathway on neocortex is excitatory by disinhibiting the upper motor neurons in the cortex (promotes movement, initiation of motor commands)
 
 ---
 
@@ -290,7 +311,7 @@ Note:
 
 Note:
 
-Overall inhibitory. Serves to modulate the disinihibitory actions of the direct pathway
+Overall effect on upper motor neuron activity in neocortex is inhibitory. Serves to modulate the disinihibitory actions of the direct pathway
 
 ---
 
@@ -576,7 +597,7 @@ Note:
 
 Function of huntingtin gene product unclear. [Null expression in mice lethal](https://doi.org/10.1016%2F0092-8674%2895%2990542-1)
 
-upregulates brain derived neurotrophic factor (BDNF). evidence that [huntingtin interacts with 19 different proteins](https://doi.org/10.1016%2FS0968-0004%2803%2900168-3)
+evidence that [huntingtin interacts with 19 different proteins](https://doi.org/10.1016%2FS0968-0004%2803%2900168-3)
 
 
 
@@ -643,7 +664,7 @@ https://www.youtube.com/watch?v=OjM9Gl_MLyQ
 * Basal ganglia are also involved in loops that modulate non-motor behaviors
 * Work in a similar way to suppress outputs
 * The limbic loop regulates emotional behavior and motivation
-* Tourette’s may be a problem with limbic loop (no longer have inhibitions about language?)
+* Tourette’s may be a problem with limbic loop (no longer have inhibitions with language selection?)
 * Drugs of abuse affect dopamine release
 * Schizophrenia, may be due to aberrant activity in limbic and prefrontal loops resulting in hallucinations disordered cognition