From 97f76cfe872f6f04147121398e759a0ebab431cc Mon Sep 17 00:00:00 2001 From: ackman678 Date: Mon, 6 Dec 2021 09:11:52 -0800 Subject: [PATCH] electric motion fin --- basal-ganglia.md | 24 +++++++++++++---- limbic.md | 48 +++++++++++++++++++--------------- motor1.md | 48 ++++++++++++++++++++-------------- motor2.md | 67 +++++++++++++++++++++++------------------------- vision1.md | 43 ++++++++++++++++++++----------- vision2.md | 10 +++++--- 6 files changed, 143 insertions(+), 97 deletions(-) diff --git a/basal-ganglia.md b/basal-ganglia.md index 4395f86..721448c 100644 --- a/basal-ganglia.md +++ b/basal-ganglia.md @@ -243,8 +243,12 @@ Note:
sign shows normal effect (excite or inhibit) at that synapse
Neuroscience 5e Fig. 18.4
-*Remember that caudate/putamen medium spiny neurons are usually not active* +
+The GABAergic projection caudate/putamen medium spiny neurons are usually pretty quiet: they have a **low baseline spike rate.** + +The GABAergic projection pallidus/reticulata neurons have a **high baseline spike rate.** +
Note: @@ -280,10 +284,16 @@ Count spikes surrounding eye movement period, y axis is count (histogram), x axi --- -## Disinhibition through the direct pathway increases activity in upper motor neurons +## Direct pathway -
Direct pathway: ctx --> putamen --> GPi --> VA/VL --> ctx
J. Ackman [CC0](https://creativecommons.org/share-your-work/public-domain/cc0/)
+
Direct pathway: ctx --> putamen --> GPi --> VA/VL --> ctx
+JA [CC0](https://creativecommons.org/share-your-work/public-domain/cc0/)
+ +
+ +Disinhibition through the **direct pathway** increases activity in upper motor neurons +
Note: @@ -306,7 +316,9 @@ Note: ## Indirect pathway -
Indirect pathway: ctx --> putamen --> GPe --> STN --> GPi --> VA/VL --> ctx
JA [CC0](https://creativecommons.org/share-your-work/public-domain/cc0/)
+
Indirect pathway: ctx --> putamen --> GPe --> STN --> GPi --> VA/VL --> ctx
+ +JA [CC0](https://creativecommons.org/share-your-work/public-domain/cc0/)
Note: @@ -434,7 +446,9 @@ Note:
Defects in the subthalamic nucleus contralateral to the involuntary movements. Reduced indirect pathway function. -
JA [CC0](https://creativecommons.org/share-your-work/public-domain/cc0/)
+
+ +JA [CC0](https://creativecommons.org/share-your-work/public-domain/cc0/)
Note: diff --git a/limbic.md b/limbic.md index 484357a..dc7d727 100644 --- a/limbic.md +++ b/limbic.md @@ -8,6 +8,9 @@ * Affective (mood) disorders– e.g. depression +
+
+ Note: emotion @@ -365,7 +368,9 @@ A white rat presented to an infant does not innately elicit fear, but pairing th
-
['Little Albert' experiment](https://en.wikipedia.org/wiki/Little_Albert_experiment), Watson and Rayner *J Exp Psychol* 1920
+
+ +['Little Albert' experiment](https://en.wikipedia.org/wiki/Little_Albert_experiment), Watson and Rayner *J Exp Psychol* 1920
Note: @@ -639,7 +644,7 @@ Note: --- -## Drugs of abuse affect dopamine projections from the VTA to the nucleus accumbens +## Substances of abuse affect dopamine projections from the VTA to the nucleus accumbens
Synaptic locations of action for psychoactive drugs of abuse
Neuroscience 5e Fig. 29.11
@@ -652,7 +657,7 @@ Exposure to drugs of abuse causes long-lasting enhancement of excitatory input t -- -## Circuits involved in drugs of abuse +## Circuits involved in substances, "drugs", of abuse * Nicotine enhances input onto VTA by presynaptic excitation * Opioids, benzodiazepines, and cannabinoids act by hyperpolarizing GABAergic neurons @@ -676,12 +681,12 @@ long-term changes addicts: -- -## Drugs of abuse act on endogenous neurotransmitter receptors and transporters +## Substances of abuse act on endogenous neurotransmitter receptors and transporters
-Drug | Endogenous ligands | Mechanism of action +Subtance | Endogenous ligands | Mechanism of action -------------- | ---------------------------- | ------------------------------------------------- Nicotine | acetylcholine | Agonist of ligand gated channels (nAChR) THC | anandamide, 2AG | Agonist of cannabinoid receptors (GPCRs) @@ -694,20 +699,18 @@ MDMA (ecstasy) | | Inhibits 5-HT transporters and V Note: -Cocaine - DAT: dopamine transporter, extracellular NET: NA transporter, extracellular -MAO: monoamine oxidase, intracellular. +MAO +: monoamine oxidase, intracellular +: Catalyzes oxidation of monoamines (serotonin, melatonin, norepinephrine, epinephrine (MAO-A) and dopamine, tyramine, tryptamine (MAO-A & MAO-B) +: bound to outer membrane of mitochondria of most cell types in the body -* : Catalyzes oxidation of monoamines (serotonin, melatonin, norepinephrine, epinephrine (MAO-A) and dopamine, tyramine, tryptamine (MAO-A & MAO-B) -* : bound to outer membrane of mitochondria of most cell types in the body. - -VMAT2: vesicular monoamine transporter, intracellular - -: blocking VMAT2 can cause reverse transport direction (cytosol to synaptic cleft) for monoamine transporters. Particularly for MDMA and amphetamines +VMAT2 +: vesicular monoamine transporter, intracellular +: blocking VMAT2 can cause reverse transport direction (cytosol to synaptic cleft) for monoamine transporters. Particularly for MDMA and amphetamines : SLC18A2 gene @@ -718,22 +721,27 @@ VMAT2: vesicular monoamine transporter, intracellular --- -## Addictive drugs hijack the brain’s reward system by enhancing the action of VTA dopamine neurons +## Addictive substances hijack the brain’s reward system by enhancing the action of VTA dopamine neurons -* Drug addiction: compulsive drug use despite long-term negative consequences +* Addiction: compulsive subtance intake despite long-term negative consequences * All drugs of abuse increase dopamine concentration at the output targets of the ventral tegmental area * Nucleus accumbens– processes reward information * Prefrontal cortex– goal selection and decision making Note: + +What is or is not a "drug"? Is it well defined by authoritative entities? + + --- diff --git a/motor1.md b/motor1.md index 4266b0d..45799c5 100644 --- a/motor1.md +++ b/motor1.md @@ -1,7 +1,7 @@ ## Movement * Movement is the planning, coordination & execution of a motor program that relies on information provided by the sensory system -* Movement is controlled by the motor systems of the brain and spinal cord +* Movement is controlled by the motor systems of the spinal cord and the brain * Motor systems translate neural signals into contractile force in muscles * Allows us to maintain balance and posture, move our body, limbs, eyes, tongue & communicate through speech @@ -79,7 +79,8 @@ Note: * Each muscle fiber is innervated by only one motor neuron. Group of muscle fibers in a muscle innervated by a single motor neuron is a motor unit * twitch happens after small small latency, 5-10 ms -TODO: motor neuron AP --> muscle fiber EPP --> muscle fiber AP. AP and Vm in muscle fiber, latency, and muscle tension rise and decay + +todo: motor neuron AP --> muscle fiber EPP --> muscle fiber AP. AP and Vm in muscle fiber, latency, and muscle tension rise and decay --- @@ -190,7 +191,7 @@ motor unit * motor unit in soleus (important for posture) has ~180 muscle fibers/per motor neuron * gastrocnemius has large and small motor units with 1000-2000 muscle fibers per motor neuron. Generates forces for sudden changes in body position. * extraocular motor units very small (~3 fibers/unit). High proportion of fibers that can contract at max velocity -* but lots of use dependent motor unit plasticity (atheletes, hypogravity conditions) +* but lots of use dependent motor unit plasticity (athletes, hypogravity conditions) + --- @@ -589,15 +594,12 @@ Note: ---- +-- ## Flexion reflex video summary
Neuroscience 5e Animation 16.2
-Note: - - --- @@ -636,7 +638,9 @@ Note: * Defects in spinal cord connectivity interrupt pattern generation * [cell article](http://www.cell.com/action/doSearch?searchType=quick&searchText=locomotion+eph&occurrences=all&journalCode=&searchScope=fullSite&contentType=video&startPage=) -* activating the mesencephalic locomotor region can trigger locomtion and change speed of movement by amount of input to spinal cord. Transection at thoracic level will still allow for coordinated locomotor movements. But not just a stretch reflex, due to CPGs present for each limb. These are all connected together in spanning circuits. Transection not allow for good walking in humans though-- maybe bipedalism requires more upper motor neuron control because of greater postural control requirements... +* Activating the mesencephalic locomotor region can trigger locomtion and change speed of movement by amount of input to spinal cord. +* Transection at thoracic level will still allow for coordinated locomotor movements. It is not only a stretch reflex, because there are CPGs present for each limb. The CPGs are all connected together in circuits spanning spinal cord segments. +* However human locomotion requires more descending input from the brain-- Transection would not allow for good walking in humans-- perhaps bipedalism requires more upper motor neuron control due to the greater postural control requirements --- @@ -652,10 +656,14 @@ S Grillner, P Zangger. On the central generation of locomotion in the low spinal ## Central pattern generator circuit model for swimming -
Lamprey
[CC0](https://en.wikipedia.org/wiki/Lamprey)
+
Lamprey
+ +[CC0](https://en.wikipedia.org/wiki/Lamprey)
Simplified lamprey CPG model. E, excitatory; I, inhibitory; M, motor neuron -
J. Ackman, [CC0](https://wiki.creativecommons.org/wiki/CC0). Based on Grillner et al., *Brain Res Rev* 2008
+
+ +J. Ackman, [CC0](https://wiki.creativecommons.org/wiki/CC0). Based on Grillner et al., *Brain Res Rev* 2008
- - -Note: - -Today we will begin our examination of the pathways in the nervous system that modulate and give rise to volitional control of our skeletal muscles. - -Recall– - -lower motor neurons -: are the neurons that make synapses with muscle fibers -: located in ventral horn of the spinal cord gray matter and cranial nerve nuclei of the brainstem - - -TODO: replace chart - ---- - - ## Upper motor neuron control * Upper motor neuron axons regulate the excitability of lower motor neuron circuits in the brainstem and spinal cord @@ -35,6 +11,27 @@ posture : a position of person's body when standing or sitting : a particular post adopted by an animal, interpreted as a signal of a specific pattern of behavior +-- + +## Neural systems that control movement + +
Neuroscience 5e Fig. 16.1
+ +
+ +
+ +Note: + +We will begin our examination of the pathways in the nervous system that modulate and give rise to volitional control of our skeletal muscles. + +Recall– + +lower motor neurons +: are the neurons that make synapses with muscle fibers +: located in ventral horn of the spinal cord gray matter and cranial nerve nuclei of the brainstem + + --- @@ -92,11 +89,11 @@ Note: Note: -Medial ventral horn has lower motor neurosn for posteure balance and orienting movements of head and neck during shits of visual gaze. Receive descending input from the pathways orginating mainly in the brainstem, course through the anterior medial white matter of the spional cord and terminate bilaterally. +Medial ventral horn has lower motor neurons for posture, balance, and orienting movements of head and neck during shits of visual gaze. Receive descending input from the pathways originating mainly in the brainstem, course through the anterior medial white matter of the spinal cord and terminate bilaterally. Lateral ventral horn contains lower motor neurons that mediate skilled voluntary movements of the distal extremities. Receive descending projection from the contralateral motor cortex via lateral division of the corticospinal tract. -*First lets discuss the upper motor neurons of the brainstem* +Next, lets discuss the upper motor neurons of the brainstem. --- @@ -127,7 +124,7 @@ There are actually both crossed and uncrossed vestibular projections.
-* Reticular formation +* Reticular formation * Complex network of circuits located in the core of the brainstem-from midbrain to medulla * Receives input from motor cortex, hypothalamus, brainstem * Project to medial regions of spinal gray matter (**reticulospinal tract**) @@ -139,14 +136,14 @@ There are actually both crossed and uncrossed vestibular projections. Note: -Reticular formation neurons functions -: cardiovascular (regulate output of nucleus ambiguous) and respiratory control (ventrolateral medulla) +Reticular formation neurons functions +: cardiovascular (regulate output of nucleus ambiguous) and respiratory control (ventrolateral medulla) : sensory motor reflexes : coordination of eye movements -: regulation of sleep and wakefulness -: coordination of limb and trunk movments -: netlike, difficult to recognize distinct neuronal clusters -: does not have a uniform function as thought classically +: regulation of sleep and wakefulness +: coordination of limb and trunk movements +: netlike, difficult to recognize distinct neuronal clusters +: does not have a uniform function as thought classically * rostral portions (mesencephalic and pontine) of reticular formation modulate forebrain activity (Moruzzi and Magoun EEG Clin. Neurophys 1949) @@ -154,7 +151,7 @@ Reticular formation neurons functions * "reticular activating system" * caudal portions involved in premotor coordination of lower somatic and visceral motor neuron pools -feedforward postural control. stabilization during ongoing movements. +Feedforward postural control. Stabilization during ongoing movements. *Reticulospinal tract is uncrossed (except for commisural spinal segment collaterals?)* @@ -173,7 +170,7 @@ Note: * rostral portions (gold, mesencephalic and pontine) of reticular formation modulate forebrain activity (Moruzzi and Magoun EEG Clin. Neurophys 1949) * cholinergic neurons (superior cerebellar peduncle) and noradrenergic neurons (locus coeruleus) and serotonergic neurons (raphe nuclei) * "reticular activating system" -* caudal portions (red) involved in premotor coordination of lower somatic and visceral motor neuron pools +* caudal portions (red) are upper motor neurons involved in coordination of lower somatic and visceral motor neuron pools --- diff --git a/vision1.md b/vision1.md index f475879..03e227e 100644 --- a/vision1.md +++ b/vision1.md @@ -4,14 +4,17 @@ * We can do this at many different intensities of light from faint light to bright sunlight * Two main components of the CNS are responsible for this: the retina in the eye and the visual centers of the brain -
[H. Kolb Webvision, med.utah.edu](http://webvision.med.utah.edu/book/part-i-foundations/gross-anatomy-of-the-ey/)
+
+ +[H. Kolb Webvision, med.utah.edu](http://webvision.med.utah.edu/book/part-i-foundations/gross-anatomy-of-the-ey/)
Note: -## Today’s learning goals + +Learning goals: * Identify the major parts of eye and retinal anatomy and their functions -* Understand the main proteins involved in the signal transduction pathway that leads to changes in neurotransmitter release by photoreceptors in response to light +* Become aware of the main proteins involved in the signal transduction pathway that lead to changes in membrane potential, calcium flux, and ultimately changes in amount of neurotransmitter released by photoreceptive cells in response to light * Learn the neural pathway that takes information from photoreceptors to the brain * Understand the concept of the receptive field @@ -68,7 +71,9 @@ Accommodation to focusing on near objects involves the contraction of the ciliar
Neuroscience 5e Fig. 11.2
-
Distance and near object focus
CC BY-SA 2.5 [commons.wikimedia](https://commons.wikimedia.org/wiki/File:Focus_in_an_eye.svg)
+
Distance and near object focus
+ +CC BY-SA 2.5 [commons.wikimedia](https://commons.wikimedia.org/wiki/File:Focus_in_an_eye.svg)
Note: @@ -97,9 +102,9 @@ Pupil has circular muscles that contract when pupil closes, and radial bands of Note: -Getting old lens loses elasticity with age. +The lens loses elasticity with age (trouble focusing on near objects). -diopter (us), is a unit of measurement of the optical power of a lens or curved mirror, which is equal to the reciprocal of the focal length measured in metres (that is, 1/metres) +diopter is a unit of measurement of the optical power of a lens or curved mirror, which is equal to the reciprocal of the focal length measured in metres (that is, 1/metres) --- @@ -109,7 +114,9 @@ diopter (us), is a unit of measurement of the optical power of a lens or curved * Floaters– happens when the vitreous slowly shrinks, it becomes stringy and the strands cast a shadow on the retina * Refractive errors, near and far sightedness -
[cataracts, Mayo Clinic](http://www.mayoclinic.org/diseases-conditions/cataracts/home/ovc-20215123)
+
+ +[cataracts, Mayo Clinic](http://www.mayoclinic.org/diseases-conditions/cataracts/home/ovc-20215123)
Note: @@ -206,7 +213,9 @@ high degree of convergence, together with more direct path in and near fovea (on
Neuroscience 5e Fig. 11.5
-
[H. Kolb Webvision, med.utah.edu](http://webvision.med.utah.edu/book/part-i-foundations/gross-anatomy-of-the-ey/)
+
+ +[H. Kolb Webvision, med.utah.edu](http://webvision.med.utah.edu/book/part-i-foundations/gross-anatomy-of-the-ey/)
Neuroscience 5e Ch. 11
@@ -304,9 +313,8 @@ Note: Note: -Four types of cone opsins in vertebrates (LWS, SWS1, SWS2, and Rh2) - -[from: https://en.wikipedia.org/wiki/Opsin](https://en.wikipedia.org/wiki/Opsin) +There are four types of cone photoreceptor opsins in vertebrates (LWS, SWS1, SWS2, and Rh2) +[https://en.wikipedia.org/wiki/Opsin](https://en.wikipedia.org/wiki/Opsin) name | abbr | type | bandwidth | color | human gene --- | --- | --- | --- | --- | --- @@ -316,6 +324,9 @@ short-wave sensitive 2 | SWS2 | cone | 400–470 nm | violet, blue (extinct in t rhodopsin-like 2 | Rh2 | cone | 480–530 nm | green (extinct in mammals) | rhodopsin-like 1 (vertebrate rhodopsin) | Rh1 | rod | ~500 nm | blue-green | OPN2 = Rho = human rhodopsin + +Non-cone opsins expressed in vertebrate tissue include melanopsin *OPN4* + Melanopsin OPN4 : circadian rhythms, pupillary reflex, and color correction in high-brightness situations : expressed in a small fraction of retinal ganglion neurons distributed across retina @@ -325,8 +336,8 @@ therian mammals : eutherians (placental mammals) and metatherians (marsupials) : not egg laying monotremes -Interesting table, [Opsins in the human eye, brain, and skin](https://en.wikipedia.org/wiki/Opsin) +Opsins of "Type I" are ion channels and are found in most life forms ( >Like type II opsins, type I opsins have a seven transmembrane domain structure similar to that found in eukaryotic G-protein coupled receptors. @@ -603,15 +614,17 @@ Note: --> --- + + --- ## Rods and cones summary diff --git a/vision2.md b/vision2.md index f8ed5c9..5a6a380 100644 --- a/vision2.md +++ b/vision2.md @@ -62,6 +62,7 @@ Note:
+ [atropa belladona](https://en.wikipedia.org/wiki/Atropa_belladonna) :'deadly nightshade' : atropine @@ -205,10 +206,13 @@ Note:
-
Human LGN
[Brain Biodiversity Bank MSU, NSF](https://msu.edu/~brains/brains/human/coronal/montage.html)
+
Human LGN
+ +[Brain Biodiversity Bank MSU, NSF](https://msu.edu/~brains/brains/human/coronal/montage.html)
+ Neurons along the dotted line see the same point in visual space. Neurons in different layers receive info from different types of RGCs.
@@ -646,11 +650,11 @@ responses of a monkey’s neuron in their homologous area to the fusiform gyrus fusiform gyrus : long strip of cortex in ventral temporal lobe, tracking along hippocampal gyrus in rostral-caudal extent, but separate from entorhinal or parahippocampal cortex -macaque monkey, http://jn.physiology.org/content/46/2/369 +macaque monkey, https://jn.physiology.org/content/46/2/369 color synesthesia: association of colors with certain numbers, letters, or objects -prosopagnosia: face blindness. Our patient Dr. P from earlier? +prosopagnosia: face blindness. See the story of patient Dr. P from Dr. O. Sack's classic clinical tales book "The Man Who Mistook His Wife for a Hat" ---