f2018 lectures end

neurotransmitters1.md

@@ -646,14 +646,13 @@ Note:
 * Found primarily in groups of neurons in the raphe region of the pons and upper brainstem
 * The raphe nucleus projects widespread in forebrain areas that are implicated in sleep and wakefulness and mood
 
-*See Fig. 6.17 Neuroscience 6e*
 
 Note:
 
 * dorsal raphe and median raphe nuclei. In brain stem. raphe nuclei just ventral to the 4th ventricle stretching from medulla
 * vesiclular monoamine transporter **VMAT** loads this (as well as other monoamines) into synaptic vesicles.
 
-turkey/tryptophan—> sleep? Yes— but not really ([http://www.snopes.com/food/ingredient/turkey.asp](http://www.snopes.com/food/ingredient/turkey.asp)), you’d have to eat a lot more (maybe 3x more) than at a particular meal. And furthermore, lots of protein sources include amounts of tryptophan similar to or greater than that of turkey per gram of food content (including eggs, fish, cheese, also nuts, seeds, legumes).
+turkey/tryptophan—> sleep? Yes— but not really ([http://www.snopes.com/food/ingredient/turkey.asp](http://www.snopes.com/food/ingredient/turkey.asp)), you’d have to eat a lot more (maybe 3x more) than at a particular meal. And furthermore, lots of protein sources include amounts of tryptophan similar to or greater than that of turkey per gram of food content (including eggs, fish, cheese, and some nuts, seeds, legumes). Tryptophan is present in all proteins, but is also
 
 And besides well timed carbohydrate ingestion with/after tryptophan consumption is important for increasing tryptophan transport from blood vessels and into brain tissue:
 
@@ -661,9 +660,15 @@ And besides well timed carbohydrate ingestion with/after tryptophan consumption
 
 >The small, all-carbohydrate snack is tryptophan's ticket across the blood-brain barrier, where it can boost serotonin levels. 
 
+Tryptophan competes with other large aromatic neutrally charged amino acids for passage into brain from blood vessels. But tryptophan is the only amino acid known to bind non-covalently with serum albumin (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1133271/?page=1) (Curzon, 1973; Smith and Pogson, 1980). This is thought to protect it from insulin induced cellular metabolism (insulin rising after eating carbohydrates of course) by bringing tryptophan to high enough concentrations in blood to favor entry into brain. Indicates that the timing of carbohydrate ingestion may be helpful.
+
+Study looking at food/protein composition type and quantitative mesaures of cerebral serotonin levels after consumption (5-HT levels can change 8-fold in rat): https://doi.org/10.1016/j.physbeh.2009.05.004
+
+
 
 ---
 
+
 ## Histamine
 
 * Made from histidine, a metabolite of monoamine oxidase
@@ -671,7 +676,6 @@ And besides well timed carbohydrate ingestion with/after tryptophan consumption
 * Mediates arousal and attention
 * Histamine receptors are in the immune system and in the CNS. Sedative effects of diphenhydramine (Benadryl) act through the CNS
 
-*See Fig. 6.17 Neuroscience 6e*
 
 Note:
 
@@ -689,8 +693,21 @@ diphenhydramine
 : also has some serotonin reuptake inhibitor capability  
 : also has some anticholinergic (muscarinic) capability   
 
+---
+
+## Projections from serotonergic and histaminergic neurons
+
+These projections are sparse (low synapse density) but widespread (most brain regions).
+
+<figure>
+<figcaption class="big">histaminergic axons from tuberomamillary nucleus of hypothalamus,  
+serotonergic axons from dorsal raphe nucleus of brain stem
+</figcaption>
+<img src="figs/Neuroscience5e-Fig-06.13-0_2e4abbc.jpg" width="800px"><figcaption>Neuroscience 6e Fig. 6.17, 5e Fig. 6.13</figcaption></figure>
+
 --
 
+
 ## Synthesis of histamine and serotonin
 
 <figure><img src="figs/Neuroscience5e-Fig-06.14-0_e342a8b.jpg" height="400px"><figcaption>Neuroscience 5e Fig. 6.14</figcaption></figure>