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Neuronal Regulation of the Immune System in Cardiovascular Diseases
Published in Shyam S. Bansal, Immune Cells, Inflammation, and Cardiovascular Diseases, 2022
Daniela Carnevale, Giuseppe Lembo, Marialuisa Perrotta, Lorenzo Carnevale
The circumventricular organs (CVOs), located around the third and fourth ventricles, are particular brain regions characterized by a leaky blood–brain barrier (BBB) and dense vascularization (Ballabh, Braun, & Nedergaard, 2004). These specialized areas are points of communication between the blood, the brain parenchyma, and the cerebrospinal fluid. The peripheral nervous system (PNS) connects the CNS to peripheral tissues and is mainly organized in two branches comprising the somatic and autonomic systems. Each of these systems further consists of two arms of sensory or afferent neurons – transporting the information from the periphery to the CNS – and motor or efferent neurons, delivering responses toward the effector tissues (Reardon et al., 2018). Additionally, the humoral route regulated by the hypothalamus-pituitary-adrenal axis provides further control of neuroimmune communication in health and disease.
Serotonin Modulation of Gastrointestinal Motility
Published in T.S. Gaginella, J.J. Galligan, SEROTONIN and GASTROINTESTINAL FUNCTION, 2020
Marcello Tonini, Fabrizio De Ponti
The GI tract can carry out most of its functions in the absence of extrinsic nerves, which play a modulatory role on intrinsic reflexes and can integrate motor events in widely separated regions of the GI tract. The discharge of autonomic efferent neurons is in turn modulated by sensory autonomic input conveyed from the gut to the central nervous system. In this section, we will give a brief summary of studies suggesting a role for 5-HT in the brain-gut axis (see also Chapter 7).
Biological Basis of Behavior
Published in Mohamed Ahmed Abd El-Hay, Understanding Psychology for Medicine and Nursing, 2019
Neurons are differentiated according to their function into sensory and afferent neurons that carry information from the sensory receptors, and motor or efferent neurons that transmit information to the muscles and glands. Interneurons are the most common type of neurons, and are located primarily within the central nervous system (CNS) and are responsible for communication among the neurons. Interneurons allow the brain to combine the multiple sources of available information to create a coherent picture of the sensory information being conveyed.
Communication between the gut microbiota and peripheral nervous system in health and chronic disease
Published in Gut Microbes, 2022
Tyler M. Cook, Virginie Mansuy-Aubert
Neuronal transmission allows for nearly instantaneous processing of sensory input or generation of motor output. This rapid signaling of peripheral neurons in the gut is critical for homeostatic mechanisms such as GI motility, secretion, and even immune response modulation.39 The peripheral nervous system (PNS) consists of vagal and spinal sensory (afferent) neurons, autonomic motor (efferent) neurons, and enteric neurons (Figure 2). Afferent neurons send information from the periphery to the brain or spinal cord, while efferent neurons project out from the central nervous system (CNS) to peripheral organs. Classifying by anatomical distribution, the twelve cranial nerves project from the brain/brainstem and spinal nerves from the spinal cord. The autonomic system is divided into sympathetic, parasympathetic, and enteric nervous systems (ENS).
Lower limb muscle synergies during walking after stroke: a systematic review
Published in Disability and Rehabilitation, 2020
Tamaya Van Criekinge, Jordi Vermeulen, Keanu Wagemans, Jonas Schröder, Elissa Embrechts, Steven Truijen, Ann Hallemans, Wim Saeys
The results of this review indicate that the synergies are altered during hemiplegic gait and that merging of synergies occurs. However, it is still unclear if these synergies are pathological or learned behavior. Although we found several reoccurring and distinctive synergies, no clear consensus can be reached concerning the amount and composition of synergies between studies. It might be that muscle synergies are dependent on the severity of the lesion and if the neural structures required for the activation of the synergies are affected. It is important to further investigate the underlying mechanisms responsible for the merging of synergies since they are an important predictor for poor motor outcome [13,20,29]. In general, a higher number of synergies was associated with intact motor function. Moreover, less synergies was related to poor improvements in muscle strength and gait kinematics [29]. Studies showed that although stroke survivors showed similar synergy strength and muscle weightings, observed changes in muscle synergies were mostly the cause of reduced muscle participation of individual muscles to a muscle synergy, impaired activation timing of a certain synergy or the ability to differentially activate the synergies [22,26,27]. It is also important to consider that different muscle synergies are observed between the paretic and non-paretic side. Although, some studies concluded that the non-paretic side had a similar synergy amount as healthy individuals, a small shift in composition was observed [22–24]. It is possible that, although contralesional efferent neurons are still intact, impairments of the paretic side influence the non-paretic side. Therefore, we recommend investigating both the paretic and non-paretic side since clear differences were found between both limbs.
Engineered nanoparticle exposure and cardiovascular effects: the role of a neuronal-regulated pathway
Published in Inhalation Toxicology, 2018
In an in vivo study, we found that acute pulmonary exposure to an engineered TiO2 particle aerosol at a concentration of 6 mg/m3 and an exposure duration of 4 hours did not increase peripheral blood levels of pro-inflammatory cytokines, such as TNF-α and IL-1 (Kan et al., 2012), both of which are known to have negative ionotropic effects on cardiac function (Ahmad et al., 2009; Dhingra et al., 2009; Zanotti-Cavazzoni and Hollenberg, 2009). In the same study, we did not detect an increase of neutrophils in the peripheral blood or enhanced ROS in the cardiac tissue (Kan et al., 2012). These results suggested that pulmonary exposure to engineered TiO2 nanoparticles did not lead to significant systemic inflammation or oxidative stress even though it may cause inflammation at the site of lung deposition. However, this study found that pulmonary exposure to nano-TiO2 greatly increased substance P, a neuronal transmitter, synthesis in the nodose ganglia, which is associated with activation of sensory receptors in airways (Figure 2). Interestingly, blocking sensory receptor activation with the transient receptor potential (TRP) channel blocker ruthenium red (RR), not only inhibited substance P synthesis in nodose ganglia, but also prevented the nano-TiO2-induced alteration in cardiac diastolic function and the increase of blood pressure (Figures 2–4) (Kan et al., 2014). The nodose ganglia are known to be involved in the integration and control of lung and heart function by receiving primary sensory nerve fibers from the lungs and transmitting that information to the brainstem’s medullary respiratory and cardiovascular regulatory centers (Spyer, 1982). It was also reported that nodose ganglia’s efferent neurons project to different chambers of the rat heart and exhibit a variety of neurochemical phenotypes (Guic et al., 2010; Kosta et al., 2010). Our observations demonstrated that pulmonary exposure to engineered TiO2 nanoparticles may cause adverse effects on the cardiovascular system by altering autonomic neuronal function through the nodose ganglia. The results from our study support the suggestion that a neurogenic mechanism could be responsible for alterations observed in cardiovascular function following pulmonary exposure to engineered nanoparticles.