MentalHealthDaily

TMEV Viral Parkinson’s Mouse Model Caused 20-Week Dopamine-Lesion Behaviors

by GLOOM

MHD featured image for a viral Parkinson's mouse model using Theiler's murine encephalomyelitis virus.

A 2026 mouse study found that Theiler’s murine encephalomyelitis virus (TMEV) injected into the substantia nigra produced persistent Parkinson’s-like motor signals through 20 weeks, including apomorphine-induced rotations at every measured post-injection timepoint.1 The finding makes TMEV a useful viral-neuroinflammation model of dopamine-neuron injury, but it does not show that Theiler’s virus causes human Parkinson’s disease. …

Entorhinal Dopamine Fails Early in Alzheimer’s Mice

by GLOOM

Editorial card showing the lateral entorhinal cortex with dopamine projections from the midbrain, illustrating an early-Alzheimer's mechanism finding rescued by L-DOPA in mice.

A 2026 Nature Neuroscience study from the Igarashi lab proposes a circuit-level answer for why the lateral entorhinal cortex (LEC) is the first cortical region to falter in Alzheimer’s: dopamine inputs from the VTA and substantia nigra to the LEC go functionally silent at the earliest disease stage in an APP knock-in mouse — before …

Human Substantia Nigra Neurons Tracked Prior Reward and Faster Motivation

by GLOOM

MHD featured image for substantia nigra dopamine reward-history signals.

A 2026 iScience study recorded 27 substantia nigra neurons during deep-brain-stimulation surgery in 11 Parkinson’s disease patients and found that prior reward shaped both putative dopamine-neuron firing and the next reaction time: responses were faster after a +$10 outcome than after neutral or negative outcomes (0.916 s vs. 1.017 s, p = 0.0175).1 Research Highlights …

Parkinson’s Metabolite Biomarkers Split 3 Patient Groups

by GLOOM

MHD featured image for Parkinson's disease metabolite biomarkers and patient metabolic subgroups.

A 2026 Parkinson’s disease study used gene-expression data and genome-scale metabolic modeling to predict patient-level metabolite patterns, then separated 104 patients into 3 metabolic subgroups that were partly reproduced in an independent 81-patient validation dataset. Research Highlights Patient-level modeling found heterogeneity: Abdik et al. predicted secretion tendencies for 802 analyzable metabolites across 104 postmortem substantia …