Editing Long-term memory (section)

===Neurodegenerative diseases===
Many neurodegenerative diseases can cause memory loss. Some of the most prevalent (and, as a consequence, most intensely researched) include [[Alzheimer's disease]], [[dementia]], [[Huntington's disease]], [[multiple sclerosis]], and [[Parkinson's disease]]. None act specifically on memory; instead, memory loss is often a casualty of generalized neuronal deterioration. Currently, these illnesses are irreversible, but research into stem cells, psychopharmacology, and genetic engineering holds much promise.

Those with Alzheimer's disease generally display symptoms such as getting momentarily lost on familiar routes, placing possessions in inappropriate locations, and distortions of existing memories or completely forgetting memories. Researchers have often used the [[Deese–Roediger–McDermott paradigm]] (DRM) to study the effects of Alzheimer's disease on memory. The DRM paradigm presents a list of words such as doze, pillow, bed, dream, nap, etc., but no theme word is presented. In this case, the theme word would have been "sleep." Alzheimer's disease patients are more likely to recall the theme word as being part of the original list than healthy adults. There is a possible link between longer encoding times and increased [[false memory]] in LTM. The patients end up relying on the gist of the information instead of the specific words themselves.<ref>{{cite journal | last1 = MacDuffie | first1 = E. K. | last2 = Atkins | first2 = S. A. | last3 = Flegal | first3 = E. K. | last4 = Clark | first4 = M. C. | last5 = Reuter-Lorenze | first5 = A. P. | year = 2012 | title = Memory distortion in Alzheimer's Disease: deficient monitoring of short-and long-term memory | journal = Neuropsychology | volume = 26 | issue = 4| pages = 509–516 | doi = 10.1037/a0028684 | pmc = 3389800 | pmid=22746309}}</ref> Alzheimer's disease leads to an uncontrolled inflammatory response brought on by extensive amyloid deposition in the brain, which leads to cell death in the brain. This gets worse over time and eventually leads to cognitive decline after the loss of memory. Pioglitazone may improve cognitive impairments, including memory loss, and may help protect long-term and visuospatial memory from neurodegenerative diseases.<ref>{{cite journal | last1 = Gupta | first1 = R. | last2 = Gupta | first2 = K.L. | year = 2012 | title = Improvement in long-term and visuo-spatial memory following chronic pioglitazone in mouse model of Alzheimer's disease | journal = Pharmacology Biochemistry and Behavior | volume = 102 | issue = 2| pages = 184–190 | doi=10.1016/j.pbb.2012.03.028 | pmid=22503969| s2cid = 8697409 }}</ref>

Parkinson's disease patients have problems with cognitive performance; these issues resemble those seen in frontal lobe patients and can often lead to dementia. It is thought that Parkinson's disease is caused by degradation of the dopaminergic mesocorticolimbic projection originating from the ventral tegmental area. It has also been indicated that the hippocampus plays an important role in episodic and spatial (parts of LTM) memory, and Parkinson's disease patients have abnormal hippocampuses resulting in abnormal LTM functioning. L-dopa injections are often used to try to relieve Parkinson's disease symptoms, as well as behavioral therapy.<ref>{{cite journal | last1 = Costa | first1 = C. | last2 = Sgobio | first2 = C. | last3 = Siliqueni | first3 = S. | last4 = Tozzi | first4 = A. | last5 = Tantucci | first5 = M. | last6 = Ghiglieri | first6 = V. | last7 = Filippo | first7 = D.M. | last8 = Pendolino | first8 = V. | last9 = De Iure | first9 = A. | last10 = Marti | first10 = M. | last11 = Morari | first11 = M. | last12 = Spillantini | first12 = G.M. | last13 = Latagliata | first13 = C.E. | last14 = Pascucci | first14 = T. | last15 = Puglisi-Allegra | first15 = S. | last16 = Gardioni | first16 = F. | last17 = DiLuca | first17 = M. | last18 = Picconi | first18 = B. | last19 = Calabresi | first19 = P. | year = 2012 | title = Mechanisms underlying the impairment of hippocampal long-term potentiation and memory in experimental Parkinson's disease | journal = Brain | volume = 135 | issue = 6| pages = 1884–1899 | doi = 10.1093/brain/aws101 | pmid=22561640| hdl = 2434/211210 | url = https://air.unimi.it/bitstream/2434/211210/2/Brain-2012-Costa-1884-99.pdf | doi-access = free }}</ref>

Schizophrenia patients have trouble with attention and executive functions, which in turn affects LTM consolidation and retrieval. They cannot encode or retrieve temporal information properly, which causes them to select inappropriate social behaviors. They cannot effectively use the information they possess. The prefrontal cortex, where schizophrenia patients have structural abnormalities, is involved with the temporal lobe and also affects the hippocampus, which causes their difficulty in encoding and retrieving temporal information (including LTM).<ref>{{cite journal | last1 = Langraf | first1 = S. | last2 = Steingen | first2 = J. | last3 = Eppert | first3 = Y. | last4 = Neidermeyer | first4 = U. | last5 = Elke | first5 = U. | last6 = Krueger | first6 = F. | year = 2011 | title = Temporal Information Processing in Short- and Long-Term Memory of Patients with Schizophrenia | journal = PLOS ONE | volume = 6 | issue = 10| pages = 1–10 | doi = 10.1371/journal.pone.0026140 | bibcode = 2011PLoSO...626140L | pmid=22053182 | pmc=3203868| doi-access = free }}</ref>