Search results for "cortex"
showing 10 items of 1827 documents
Early auditory processing in musicians and dancers during a contemporary dance piece
2016
AbstractThe neural responses to simple tones and short sound sequences have been studied extensively. However, in reality the sounds surrounding us are spectrally and temporally complex, dynamic and overlapping. Thus, research using natural sounds is crucial in understanding the operation of the brain in its natural environment. Music is an excellent example of natural stimulation which, in addition to sensory responses, elicits vast cognitive and emotional processes in the brain. Here we show that the preattentive P50 response evoked by rapid increases in timbral brightness during continuous music is enhanced in dancers when compared to musicians and laymen. In dance, fast changes in brigh…
Auditory and Cognitive Deficits Associated with Acquired Amusia after Stroke: A Magnetoencephalography and Neuropsychological Follow-Up Study
2010
Acquired amusia is a common disorder after damage to the middle cerebral artery (MCA) territory. However, its neurocognitive mechanisms, especially the relative contribution of perceptual and cognitive factors, are still unclear. We studied cognitive and auditory processing in the amusic brain by performing neuropsychological testing as well as magnetoencephalography (MEG) measurements of frequency and duration discrimination using magnetic mismatch negativity (MMNm) recordings. Fifty-three patients with a left (n = 24) or right (n = 29) hemisphere MCA stroke (MRI verified) were investigated 1 week, 3 months, and 6 months after the stroke. Amusia was evaluated using the Montreal Battery of …
PPAR-γ Agonist GW1929 But Not Antagonist GW9662 Reduces TBBPA-Induced Neurotoxicity in Primary Neocortical Cells
2013
Tetrabromobisphenol A (2,2-bis(4-hydroxy-3,5-dibromophenyl)propane; TBBPA) is a widely used brominated flame retardant. TBBPA induces neuronal damage, but the mechanism by which this occurs is largely unknown. We studied the possible involvement of peroxisome proliferator-activated receptor gamma (PPAR-γ) in TBBPA-induced apoptosis and toxicity in mouse primary neuronal cell cultures. TBBPA enhanced both, caspase-3 activity and lactate dehydrogenase (LDH) release in neocortical cells after 6 and 24 h of exposition. These data were supported at the cellular level with Hoechst 33342 staining. Immunoblot analyses showed that, compared with control cells, 10 μM TBBPA decreased the expression of…
Frequency-specific network activity predicts bradykinesia severity in Parkinson’s disease
2021
Highlights • Parallel subnetworks are affected in bradykinesia. • The primary motor and the premotor cortex are common nodes with task-specificity. • Beta activity decreases, gamma activity increases with improvement of bradykinesia. • Subthalamic stimulation reduces beta, increases gamma power in ipsilateral cortex. • Subnetworks act with frequency-specific oscillations.
New scenarios for neuronal structural plasticity in non-neurogenic brain parenchyma: the case of cortical layer II immature neurons
2011
The mammalian central nervous system, due to its interaction with the environment, must be endowed with plasticity. Conversely, the nervous tissue must be substantially static to ensure connectional invariability. Structural plasticity can be viewed as a compromise between these requirements. In adult mammals, brain structural plasticity is strongly reduced with respect to other animal groups in the phylogenetic tree. It persists under different forms, which mainly consist of remodeling of neuronal shape and connectivity, and, to a lesser extent, the production of new neurons. Adult neurogenesis is mainly restricted within two neurogenic niches, yet some gliogenic and neurogenic processes a…
Palaeohistology and palaeopathology of an Aeolosaurini (Sauropoda: Titanosauria) from Morro do Cambambe (Upper Cretaceous, Brazil)
2021
A recent publication of fossil bones of titanosaurs assigned to Aeolosaurini from the Morro do Cambambe site (Mato Grosso state, Brazil, Upper Cretaceous) reported anomalous growth in some of them. Here, we present osteohistological sections of elements to understand not only the microstructure and growth of such bones, but also the nature of those anomalies. Among them, we selected one cervical and one mediumposterior dorsal rib, and a haemal arch. The primary bone of all specimens consisted of a variation of the fibrolamellar complex, with the inner cortex being rich in woven bone with dispersed longitudinal canals, while the outer cortex was parallel-fibred with rows of longitudinal cana…
Neurofibrillary tangles and neuropil threads as a cause of dementia in Parkinson’s disease
1997
Alzheimer’s disease (AD) and Parkinson’s disease (PD) are the most common age-related degenerative disorders of the human brain. Both diseases involve multiple neuronal systems and are the consequences of cytoskeletal abnormalities. In AD susceptible neurons produce neurofibrillary changes, while in Parkinson’s disease, they develop Lewy bodies. In AD six developmental stages can be distinguished on account of the predictable manner in which the neurofibrillary changes spread across the cerebral cortex. During the course of PD numerous limbic determined parts of the brain undergo specific lesions regulating endocrine and autonomic functions. In general, the extranigral destructions are in t…
Neural networks engaged in milliseconds and seconds time processing: evidence from transcranial magnetic stimulation and patients with cortical or su…
2009
Here, we review recent transcranial magnetic stimulation studies and investigations in patients with neurological disease such as Parkinson's disease and stroke, showing that the neural processing of time requires the activity of wide range-distributed brain networks. The neural activity of the cerebellum seems most crucial when subjects are required to quickly estimate the passage of brief intervals, and when time is computed in relation to precise salient events. Conversely, the circuits involving the striatum and the substantia nigra projecting to the prefrontal cortex (PFC) are mostly implicated in supra-second time intervals and when time is processed in conjunction with other cognitiv…
Cortical beta burst dynamics are altered in Parkinson's disease but normalized by deep brain stimulation
2022
Funding Information: Amande Pauls was supported by a personal grant from the University of Helsinki . Olesia Korsun was supported by the Päivikki and Sakari Sohlberg Foundation , the Orion Research Foundation , the Finnish Parkinson Foundation and the Finnish Brain Foundation . Mia Liljeström was supported by the Swedish Cultural Foundation in Finland , the Päivikki and Sakari Sohlberg Foundation , and the Finnish Cultural Foundation . Eero Pekkonen was supported by Finnish Government research funding ( TYH- fund ). Hanna Renvall was supported by the Academy of Finland (grant number 321460 ) and Paulo Foundation. Publisher Copyright: © 2022 Exaggerated subthalamic beta oscillatory activity …
Alterations in membrane and firing properties of layer 2/3 pyramidal neurons following focal laser lesions in rat visual cortex.
2013
Focal cortical injuries are well known to cause changes in function and excitability of the surviving cortical areas but the cellular correlates of these physiological alterations are not fully understood. In the present study we employed a well established ex vivo-in vitro model of focal laser lesions in the rat visual cortex and we studied membrane and firing properties of the surviving layer 2/3 pyramidal neurons. Patch-clamp recordings, performed in the first week post-injury, revealed an increased input resistance, a depolarized spike threshold as well as alterations in the firing pattern of neurons in the cortex ipsilateral to the lesion. Notably, the reported lesion-induced alteratio…