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The summary of the following study presents several genotypic and phenotypic characteristics of autosomal dominant retinitis pigmentosa. This studies also attempt to describe the physiology and the progression of the disease, paying specific attention to different mutations of the RHO gene. Since RHO codes for rhodopsin, one of the unifying characteristics seen in patients with mutations in this gene is degeneration of rods (vision in low light) before the degeneration progresses to the cones. This relays into the first sign of retinitis pigmentosa which is loss of night vision and inability to navigate in low light. Young patients begin seeing blind spots in their peripheral vision as the disease gets progressively worse. The development of retinitis pigmentosa could halt at this stage however, in the majority of cases it continues to the cones and central vision begins to fail as well. In adults, retinitis pigmentosa can lead to permanent, legal blindness (Retinitis Pigmentosa, 2018). In an early study performed by Ching-Hwa Sung et al, the researchers found rhodopsin mutations in autosomal dominant retinitis pigmentosa as well (1991). They screened 161 unrelated patients with this particular mode of inheritance for point mutations in the rhodopsin gene by using PCR and gel electrophoresis. Of the 161 patients, 39 were found to carry one of 13 different point mutations at 12 amino acid positions of rhodopsin and the “presence or absence of the mutations correlated with the presence of absence of retinitis pigmentosa in 174 out of 179 individuals tested in 17 families” (Ching-Hwa Sung, 1991). These point mutations were found in the coding sequences of the RHO gene and the most common allele, P23H, was found in 15% of the ADRP families. The individual family members also experienced gradual loss of night vision and navigation in the dark. Since this is such a low, unexpected percentage, it could be concluded that there is delayed onset of the disease or very mild disease expression. This study emphasizes how with each genetic type (autosomal recessive, autosomal dominant, X-linked) there is marked individual variation. Any particular mutation in a gene, such as the rhodopsin gene RHO, is unlikely to be present in other genetic types. This presents a setback that is faced in many attempts to create treatments/cures for retinitis pigmentosa. Because of the specificity and individualism of the gene the current progress of treatment plans is very complicated and requires special attention to the patients’ conditions

Retinitis pigmentosa can be caused by genetic mutations in over 60 genes. More than 20 genes are associated with the autosomal dominant mode of inheritance. Of these 20 genes, the rhodopsin gene, RHO, is the most prevalent to cause autosomal dominant retinitis pigmentosa, and more than 45 mutations in RHO have been identified (Sung et al, 1994). Because there are so many genes that encode various structures in the retina, it is difficult to delegate a single gene to the disease. However, by studying families that show symptoms, researchers are able to locate the mutation, contribute to the scientific community and hopefully provide more explanations that will lead to treatments and cures.
The RHO gene provides instructions for making rhodopsin. Rhodopsin is the photopigment in rods that absorbs photons of light and converts it into an action potential cascade. It is made up of cis-retinal and is important for low-light conditions. When light hits rhodopsin, it begins to decompose, cis-retinal is converted to trans-retinal, and the membrane conductance for Na+ in the outer segment of the rod decreases. The electrical signals are transmitted to the brain. The fovea contains a high density of cones and is located in the macula of the retina. Here, the retinal layers are spread apart to allow light to get to the photoreceptors with minimal interference. This allows for improved resolution and higher acquity for central vision. There is a higher ratio of rods to cones around the fovea that are more responsible for peripheral vision. Since retinitis pigmentosa involves the degeneration of rods and cones, the disease can affect both peripheral, central vision, night blindness and a variety of vision disruptions in low-dimness and bright settings.

Retinitis pigmentosa is an inherited disease of the retina that affects 1 in 3,500 people and is one of the leading causes of blindness. It was first discovered and diagnosed by According to an NHGRI article “Learning About Retinitis Pigmentosa” (2013), the disease can be diagnosed at age of 10 in most cases. There are different stages of retinitis pigmentosa. Generally, one of the first common signs is the degeneration of the rod cells. This causes the patient to lose their peripheral vision and acquire tunnel vision. On the other hand, some patients’ first symptoms of retinitis pigmentosa include lose of central vision. In both instances, the progressive cone and rod breakdown causes disruption in color perception, night blindness, peripheral and/or central vision. Because of the variability presented by retinitis pigmentosa, not all patients experience these symptoms during their lifetime, and not all patients become completely blind. Unfortunately, this disease cannot be corrected with corrective lenses and there are no known cures (Learning, 2013).

“Learning about Retinitis Pigmentosa.” National Human Genome Research Institute (NHGRI), 27 Dec. 2013, www.genome.gov/13514348/learning-about-retinitis-pigmentosa/#al-5.

Retinitis pigmentosa is an inherited disease of the retina that affects 1 in 3,500 people and is one of the leading causes of blindness. It was first discovered and diagnosed by According to an NHGRI article “Learning About Retinitis Pigmentosa” (2013), the disease can be diagnosed at age of 10 in most cases. There are different stages of retinitis pigmentosa. Generally, one of the first common signs is the degeneration of the rod cells. This causes the patient to lose their peripheral vision and acquire tunnel vision. On the other hand, some patients’ first symptoms of retinitis pigmentosa include lose of central vision. In both instances, the progressive cone and rod breakdown causes disruption in color perception, night blindness, peripheral and/or central vision. Because of the variability presented by retinitis pigmentosa, not all patients experience these symptoms during their lifetime, and not all patients become completely blind. Unfortunately, this disease cannot be corrected with corrective lenses and there are no known cures (Learning, 2013).

“Learning about Retinitis Pigmentosa.” National Human Genome Research Institute (NHGRI), 27 Dec. 2013, www.genome.gov/13514348/learning-about-retinitis-pigmentosa/#al-5.

For our poster research project, we decided to count the flies, spiders and spider webs in various Morrill rooms. And see if there is any correlation with that data and how far away it is from the Morrill Greenhouses. Collecting the data was a difficult task because of the various parameters that need be taken into account when going from windowsill to windowsill. Sometimes we would walk into a room and come face to face with certain questions that we have not considered when visiting previous rooms. For instance, there are different kinds of windowsills, some windows are open and some aren't, some windows don't even have window sills. Some were very dirty and some of them we weren't able to come near due to tables being in the way. All in all, we tried our best and would make sure to include that in our paper if we were to write one.

- low Thyroid v. high Thyroid symptoms associated w/ these levels
- hypothyroidism: excothalmose, bulging eyes, 30% of patients have them
- hyperthyroidism: diagnosing these disorders is difficult b/c symptoms are not the same for everybody even tho it’s the same H
- radioimmunoassay is a way to measure thyroid hormone in you by the doctor
- measurements of thyroid hormone in blood defines thyroid diseases, can have all these symptoms but unrelated to Thyroid hormone levels is the “normal” range “normal”? how is the range measured?
- studies of populations that are the same in many ways
- exclude those w/ signs of disease
- there is a lot of variation in the population but for each individual , variation is only about 10%, they only take one measurement for you
it could be a normal value for her but it could be outside the reference age, bc of varianve of the ind
- sub-clinical TH category?
- important for pregnancy because fetus require Thyroid for development and their's don't begin to function until later on
- t4 and t3 released from T gland, but t4 comes from liver also
- t3 levels in blood aren’t indicator of T function, good indicator of t4 metabolism instead
- t4 binds to R w/ low affinity, needs to be converted to t3 to be more active
- not very soluble in water and not soluble enough in membranes that in can cross membrane by itself
-specific transporter that actively transports TH across membrane across the cell
- genetic defect in this transporter = development of very few muscles
- neither brain or muscle could take it up during development, transport is very essential (case of boy in Berlin, couldn’t talk, hold head up and had very low IQ)

- hormones act thru receptors
- [ ] of free hormone and free receptor combine, need one for the other (the equation)
- will bind and dissociate so there is a rate constant (association rate constant and rate of dissociation constant)
- association constant * the product of free hormone and free receptor = dissociation constant * HR complex
K2/K1 = KD
- disocciation and association rates don’t have to be the same but they are very important
- smaller KD, smaller [ ] of hormone req’d to bind 50% of the receptors = more potent!! (the hormone itself, more effective)
- HR [ ] = hormone bound to receptor v. adding hormone graph
- the more you add, the more is bound to the receptor
- eventually receptor won’t bind anymore and you get receptor saturation (= provides no info at all)
KD: the concentration of hormones in which 50% of the receptor is bound (50% is arbituary %age, could be something else)
2 diff [ ]s of receptors, KD is the same so point at which 50% is saturated is the same but effect is very different
the 2 receptor populations are seeing the same [hormone] but the tissues respond differently
# of receptors dictates magnitude of response and sensitivity of response
- response is measured by cGMP generation, more in 100 than in 0.2
- more receptors = greater response
- the same response will occur at lower concentrations of hormones depending on # of receptors available
- more receptors available, the same response will be achieved at a lower of [H]
- affinity for the hormone of the recptor is not the most important factor attributing to the efficacy of the hormone, this is v. important for drugs
ex: why is propafol a classic agent used as an anesthetic and yet there is a 50-fold difference sensitivity b/w field
some are more sensitive that others (metabolism isn’t the only factor, basically)

feedback pathways to V1 carry mainly excitatory input and porject preferentially to pyramidal cells
- V1 is characterized by a unique layered appearance in Nissl stained tissye = striated
magnocellular pathway: associated w/ movement of the visual image, to upper parts of the layer 4B
parvocellular pathway: associated w/ form and color, to lower parts of layer 4
- M-cells from 4C project to layer 4B and have side projections to interblob cells and now you know how B responds to input from both sides (not just contralateral or ipsilateral)
- P-cells from 4C project to more superficial layers in 2 and 3 where you see ocular dominance columns cell can respond to either eye
- critical dev. period (12wks) req’d to set up ocular dominance columns, for high acuity, depth perception
- past a certain age, wiring becomes hard-wired, a lot less plasticity
- ex: lazy-eye, patch good eye to allow the bad eye develop
- visual deprivation experiments in cats, suture eyes and study ODCs, suturing causes loss of striation patterns
- neurons in primary visual cortex respond preferentially to oriented edges (all edge orientations equally represented in visual cortex)
- different orientations of a bar on a screen and recording from layer 2/3 of V1 of a specific neuron, up and down = max burst, can graph a tuning curve and see which stimulus responded it best to
- a given orientation in a visual scene seems to be encoded by the activity of a distinct population of orientation-selective neurons
- respond to same stimulus in the same position in the VF if recording up and down (“a column”) in the V1
- similar RFs, and orientation selectivity is similar
- BUT, if you go across (R to L of the cortex), they have different RFs and different responses to different orientations of the bar as you go across
- “orderly progression of RFs and orientation selectivity”

- in the mouse, everything crosses at the chiasm, in humans it’s not the case
- axons (of RGCs) of the optic tract terminate in 4 nuclei w/in the brain:
1.) LGN: of the thalamus – for visual perception
2.) superior colliculus: of the midbrain, non-image forming – for control of eye movements
3.) SCN: of the hypothalamus, non-image forming – for control of diurnal rhythms and hormonal changes
4.) pretectum: of the midbrain, non-image forming – for control of the pupillary reflex
- LGN has 6 layers, 3-6 are v. alike and 1+2 are similar to each other (Nissl stain of ER ribosomes)
1&2 = magnocellular layer, cells are larger, contain more Nissl stain substance
3-6 = parvocellular layer
- just a relay station, inputs = outputs of the ganglion cells that then project to the primary cortex/v1/striate cortex
- alternating layers get input from RGCs
- 18 types of RGCs (ON and OFF RGCs, ON/OFF center surround RGCs, etc)
- P&M ganglion cells are specific to the primate high visual acuity and color processing systems
- classes of ganglion cells called P and M ganglion cells in primates, encode two important features of vision
- P and M project to two different parts of the LGN
- size of RFs of P and M are very different, structure related to function
M cells: (like alpha cells in cats) are important for detecting motion
- M-cells project to magnocellular layers
- M-cells are color-blind, direction sensitive, adapt to a maintained stimulus, best for detecting movement across a RF
- much larger than P-ganglion cells
- synapses w/ many bipolar cells
- large concentric RF and more sensitive to small center-surround brightness differences
- responds w/ a transient, RA response to a maintained stimulus
- responds maximally, w/ high discharge rates, to stimuli moving across its RF
P cells – high acuity b/w neighboring points in the RFs/retinas, and color sensitive (sensitive to wavelengths of light), like beta cells in cats
- not direction selective (produce weak responses), midget RGCs
- pavocellular layer receive input from the P-cells
- out# the M-ganglion cells by ~100 to 1 in the primate retina
- make synaptic contact w/ one to a few cone BCs that are innervated by foveal cones
- small concentric RF
- produces a stustained, SA response that lasts as long as a stimulus is centere in its RF
- this type of response is best suited for singlaing the presence, color ad duration of a visual stimulus and is poor for signaling
stimulus movement

Sjogren's syndrome, also known as Sicca's syndrome, is an autoimmune disease that affects various organs (pancreas and the liver) and causes severe dryness in the mouth and eyes. There are various studies on this disease but scientists are still trying to figure out the genetic and/or environmental causes. A study done in 2013 by Christopher J. Lessard looks at "variants at multiple loci implicated in both innate and adaptive immune responses are associated with Sjögren’s syndrome." The contributors to this study formed a database to contain all the information about the disease in one place along with the various case studies, in order to bring awareness to Sjogren's syndrome. Something interesting about treatment of this disease, is the invention of artificial tears to combat the extreme dryness of the eyes. Because of the long list of symptoms, it has become difficult to identify a single cause as well as a well-rounded treatment plan.