Lateral Interactions in Cortical Networks
Mark J Rowe, Yoshiaki Iwamura in Somatosensory Processing: From Single Neuron to Brain Imaging, 2001
A cortical network is a complex system that contains multiple interacting circuits, generating multiple types of lateral interactions among cortical columns. The extent and importance of these lateral interactions is only now beginning to be fully appreciated, spurred by recent major advances in anatomical and physiological experimental techniques. While this area of research is still in its early stages, and a general theory of lateral interactions is yet to emerge, we distinguish — based on our experimental and modeling work — three systems of lateral interactions that take place within a cortical area. They are: (1) the most local, minicolumnar interactions, taking place among cells located within ca. 0.1mm of each other in the plane of cortical surface;(2) intermediate, macrocolumn-range interactions, within ca. 0.5mm cortical columns; and(3) long-range interactions, among more widely separated cortical columns. We will give a brief summary of each of these three systems and then introduce what we believe is a fundamental sensory information-processing task that is carried out by these lateral interactions.
Cortical projection neurons as a therapeutic target in multiple sclerosis
Published in Expert Opinion on Therapeutic Targets, 2020
Tatjana Beutel, Julia Dzimiera, Hannah Kapell, Maren Engelhardt, Achim Gass, Lucas Schirmer
Supragranular layer pyramidal neurons are important players within the organization of functional cortical columns. Their microcircuits have been studied with great detail in particular in the rodent somatosensory system [23]. The consensus is this: in primary sensory cortical areas, thalamic input mainly reaches excitatory spiny stellate and pyramidal cells in layer IV, which then disperse information upward within the cortical column and synapse onto layer II/III pyramidal neurons. These neurons constitute the majority of callosal projections [24]. As a consequence, they contribute significantly to the integration of information from both hemispheres [19,25,26]. Of note, thalamic input also reaches infragranular layer V pyramidal neurons via direct synaptic innervation [27], and can also reach supragranular layers from here. Numerous classes of locally-projecting GABAergic interneurons provide essential control of the excitation states within the network, and the entire system relies on a delicate balance of excitation and inhibition in order to function properly [28].
How the parcellation theory of comparative forebrain specialization emerged from the Division of Neuropsychiatry at the Walter Reed Army Institute of Research
Published in Journal of the History of the Neurosciences, 2021
Sven O. E. Ebbesson
The SIP of monocular cortical columns appears to be a later evolutionary development, as, with few exceptions, only some primates, including chimpanzees (Tigges and Tigges 1979), have such columns (see Ebbesson 1980c, 1984a). All mammals, however, share ontogenetic stages in which apparently all geniculate neurons and all layer four visual cortical neurons have binocular inputs. The ontogenetic parcellation of ocular dominance columns therefore probably reflects (to an unknown degree) their evolution.
Association of reduced cortical thickness and psychopathological symptoms in patients with first-episode drug-naïve schizophrenia
Published in International Journal of Psychiatry in Clinical Practice, 2023
Huixia Zhou, Dongmei Wang, Bo Cao, Xiangyang Zhang
Cortical thickness refers to the local or average distance between the white matter surface and the pial surface of the cortex, and is a direct indicator of cortical mass. Cortical thickness indicates the arrangement, density and size of nerve fibres, neuroglia and neurons (Narr et al., 2005; Parent, 1995) in the cortical columns. Studies have found that neurogenesis, neuronal migration and differentiation and synaptogenesis are all impaired in patients of schizophrenia (Wada et al., 2020; Eisenbach-Schwartz, n.d.). These defects may influence the cortical laminae arrangement and result in morphological alternations in the cortical thickness (Narr et al., 2005). Although increased grey matter thickness indicates brain maturation, which is supposedly associated with synaptic pruning, younger children display larger cortical thickness than older children (Sowell et al., 2001). Moreover, decreases in cortical volume and thickness have been observed in adult ageing; however most notably, decreases in grey matter volumes occur in late adolescence and early adulthood (Sowell et al., 2003). Therefore, measuring cortical thickness may allow us to explore changes in brain development (Magnotta et al., 1999; Sowell et al., 2001, 2003; Salat et al., 2004) that may be a potential pathogenesis of schizophrenia (Thompson et al., 2004). In recent years, more and more studies have examined the abnormal cortical thickness in schizophrenia (Ehrlich et al., 2012; Lynn, 2016; Nenadic et al., 2015; van Erp et al., 2018; Walton et al., 2017). Recently, a meta-analysis of 4474 schizophrenia patients and 5098 controls found a general thinning of the patients’ cerebral cortex, with the most significant changes in the frontal and temporal lobe (van Erp et al., 2018). However, some studies have reported that there are also between-group differences in the cortical thickness of the occipital lobe (Sprooten et al., 2013) and parietal lobe (Kuperberg et al., 2003; Rimol et al., 2010). Findings on cortical thickness abnormalities suggest potential neuropathological abnormalities in the intrinsic structure and integrity of cortical laminae (Cortex, 1990), which may lead to neurodegeneration in the grey matter regions. The possible confusing variables that contribute to the inconsistent results may include illness chronicity, and long-term antipsychotic medication and focal atrophy of certain cortex (Fischl & Dale, 2000).
Related Knowledge Centers
- Cerebral Cortex
- Postcentral Gyrus
- Predictive Coding
- Visual Cortex
- White Matter
- Neuron
- Cortical Minicolumn
- Grey Matter
- Archicortex
- Paleocortex