Browsing by Subject "Pyramidal neurons"

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    Adaptive changes in the visual cortex after photoreceptor degeneration in retinitis pigmentosa
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Martinez Galan, Juan R.; Caminos, Elena; Biología Celular e Histología
    Retinitis pigmentosa (RP) is a group of hereditary disorders that cause progressive retinal degeneration, affecting the rods and, subsequently, the cones, which results in progressive vision loss. RP is genetically heterogeneous and is inherited in an autosomal dominant, autosomal recessive, X-linked, or sporadic non-Mendelian manner. The recent advance-ments in repairing damaged retinas highlight the necessity of understanding the impact of photoreceptor degeneration on the visual cortex. This is because functional vision may not be adequately restored if this region is significantly impaired prior to treatment. In the present review, we have analyzed the rodent models of RP that have been most frequently used and the physiological and morphological changes occurring in both humans and rodents with this disorder. Following visually evoked stimulation, the processing of visual information in the primary visual cortex (V1) of individuals with RP is altered due to modifications in the transduction of the signal originating in the degenerated retina. Moreover, alterations in the intrinsic electro-physiological properties of cortical neurons and neural circuits have also been documented. Finally, several neurochemical and/or morphological changes are observed in synaptic structures associated with pyramidal neurons and in select inhibitory interneurons. Nevertheless, despite the physiological and morphologi-cal changes that have been described, the impact of RP on the visual cortex does not inevitably result in irreversible damage, as the alterations do not appear to be particularly severe. Brain plasticity is more restricted in adults; however, remodeling of the visual cortex in mice and humans is possible, which encourages further work on therapies capable of partially restoring the lost visual function.
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    Therapeutic potential of porphyran in mitigating ischemia-reperfusion injury in gerbil hippocampus
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2026) Tae-Kyeong Lee; Joon Ha Park; Dae Won Kim; Choong-Hyun Lee; Moo-Ho Won; Il Jun Kang; Ji Hyeon Ahn; Biología Celular e Histología
    Cerebral ischemia-reperfusion (IR) injury is a critical pathological event that leads to extensive neuronal loss, neuroinflammation, and blood-brain barrier (BBB) dysfunction. Porphyran, a sulfated polysaccharide derived from Porphyra spp., has demonstrated anti-inflammatory and neuroprotective effects in various neurological conditions. This study aimed to evaluate the post-ischemic therapeutic potential of porphyran in a gerbil model of transient forebrain ischemia. Our findings reveal that porphyran administration (50 mg/kg orally once daily for five days) following IR significantly mitigated IR-induced cognitive decline, as evidenced by the Y-maze test, but porphyran treatment did not significantly prevent neuronal death in the CA1 subregion of the hippocampus, as revealed by Cresyl Violet (CV) and Fluoro-Jade B (FJB) staining. However, porphyran treatment after IR injury effectively attenuated the IR-induced decrease in acetylcholine (ACh) levels, suggesting potential preservation of cognitive function in surviving neurons. Furthermore, porphyran significantly mitigated microglial activation and reduced the levels of proinflammatory cytokines (IL-1β, IL-6, and TNF-α), indicating its anti-inflammatory properties. Additionally, porphyran administration reduced BBB disruption, as evidenced by decreased extravasation of immuno-globulin G (IgG), suggesting a role in maintaining vascular integrity. In summary, although porphyrin administration after IR does not protect pyramidal neurons directly, it may improve cognitive function by mitigating ACh depletion, suppressing microglial activation, and reducing inflammatory cytokine levels