Topic: Gfap

Dissecting the role for astrocytes in mediating adverse outcomes of maternal immune activation.

Prenatal infections cause maternal immune activation (MIA), a major risk factor for several neurodevelopmental disorders, including schizophrenia, autism spectrum disorders (ASD), and attention deficit hyperactivity disorder (ADHD). Consequently, elucidating the mechanisms by which MIA alters brain function is critical for understanding the pathophysiology of these disorders and developing effective treatments. While the effects of MIA on neurons and microglia have been extensively studied, the impact of MIA on astrocytes, key regulators of brain physiology and homeostasis, remain unknown that significantly impedes our understanding the mechanisms of MIA-induced neurobehavioral abnormalities. To address this major knowledge gap, we conducted pilot studies that suggest that MIA increases impulsivity-like behaviors and amphetamine-induced hyperactivity and enhances extracellular levels of glutamate (GLU) and dopamine (DA) in the dorsal striatum (DS). MIA also increased pro-inflammatory signatures of astrocytes, including up- regulation of the Nuclear Factor kappa B (NF-κB) pathway and increased GFAP immunoreactivity in DS astrocytes. Collectively, these novel findings support our overarching hypothesis that MIA increases astrocyte reactivity, leading to increased gliotransmission (e.g., GLU), which in turn enhances DS DA release and DA- dependent behaviors. To test this hypothesis, we will leverage the expertise of the research team in molecular, physiological and neurobehavioral approaches and conduct the following Specific Aims: In Aim 1, we will identify the MIA-induced cellular and physiological changes characteristic of astrocyte reactivity. In Aim 2, we will determine the circuit mechanisms by which MIA increases DA signaling. In Aim 3, we will identify the molecular mechanisms whereby reactive astrocytes contribute to MIA-induced cellular and behavioral abnormalities. These studies will enhance the current understanding of the effects of MIA on brain functions and generate new insight into potential treatment strategies for MIA-associated neurodevelopmental disorders.

What about antibiotics for the treatment of the dyskinesia induced by L-DOPA?

L-DOPA-induced dyskinesia is a debilitating adverse effect of treating Parkinson’s disease with this drug. New therapeutic approaches that prevent or attenuate this side effect is clearly needed. Wistar adult male rats submitted to 6-hydroxydopamine-induced unilateral medial forebrain bundle lesions were treated with L-DOPA (oral or subcutaneous, 20 mg kg-1) once a day for 14 days. After this period, we tested if doxycycline (40 mg kg-1, intraperitoneal, a subantimicrobial dose) and COL-3 (50 and 100 nmol, intracerebroventricular) could reverse LID. In an additional experiment, doxycycline was also administered repeatedly with L-DOPA to verify if it would prevent LID development. A single injection of doxycycline or COL-3 together with L-DOPA attenuated the dyskinesia. Co-treatment with doxycycline from the first day of L-DOPA suppressed the onset of dyskinesia. The improved motor responses to L-DOPA remained intact in the presence of doxycycline or COL-3, indicating the preservation of L-DOPA-produced benefits. Doxycycline treatment was associated with decreased immunoreactivity of FosB, cyclooxygenase-2, the astroglial protein GFAP and the microglial protein OX-42 which are elevated in the basal ganglia of rats exhibiting dyskinesia. Doxycycline also decreased metalloproteinase-2/-9 activity, metalloproteinase-3 expression and reactive oxygen species production. Metalloproteinase-2/-9 activity and production of reactive oxygen species in the basal ganglia of dyskinetic rats showed a significant correlation with the intensity of dyskinesia. The present study demonstrates the anti-dyskinetic potential of doxycycline and its analog compound COL-3 in hemiparkinsonian rats. Given the long-established and safe clinical use of doxycycline, this study suggests that these drugs might be tested to reduce or to prevent L-DOPA-induced dyskinesia in Parkinson’s patients.

Neuroscience Investigations in the Virgin Lands of African Biodiversity

Africa is blessed with a rich diversity and abundance in rodent and avian populations. This natural endowment on the continent portends research opportunities to study unique anatomical profiles and investigate animal models that may confer better neural architecture to study neurodegenerative diseases, adult neurogenesis, stroke and stem cell therapies. To this end, African researchers are beginning to pay closer attention to some of her indigenous rodents and birds in an attempt to develop spontaneous laboratory models for homegrown neuroscience-based research. For this presentation, I will be showing studies in our lab, involving cellular neuroanatomy of two rodents, the African giant rat (AGR) and Greater cane rat (GCR), Eidolon Bats (EB) and also the Striped Owl (SO). Using histological stains (Cresyl violet and Rapid Golgi) and immunohistochemical biomarkers (GFAP, NeuN, CNPase, Iba-1, Collagen 2, Doublecortin, Ki67, Calbindin, etc), and Electron Microscopy, morphology and functional organizations of neuronal and glial populations of the AGR , GCR, EB and SO brains have been described, with our work ongoing. In addition, the developmental profiles of the prenatal GCR brains have been chronicled across its entire gestational period. Brains of embryos/foetuses were harvested for gross morphological descriptions and then processed using immunofluorescence biomarkers to determine the pattern, onset, duration and peak of neurogenesis (Pax6, Tbr1, Tbr2, NF, HuCD, MAP2) and the onset and peak of glial cell expressions and myelination in the prenatal GCR. The outcome of these research efforts has shown unique neuroanatomical expressions and networks amongst Africa’s rich biodiversity. It is hopeful that continuous effort in this regard will provide sufficient basic research data on neural developments and cellular neuroanatomy with subsequent translational consequences.

Generation of different oligodendrocyte lineage cell states following direct lineage reprogramming of GFAP+ astrocytes

Plasma p-tau181, Aβ42/40, NfL, GFAP, and cognitive change from age 73 to 82: Lothian Birth Cohort 1936

Serum NfL and GFAP trajectories after sports-related concussion in Australian football players