Hepatic encephalopathy (HE) is a neuropsychiatric hepatic‑induced syndrome in which several factors are involved in promoting brain perturbations, with ammonia being the primary factor. Motor impairment, incoordination, and gut dysbiosis are some of the well‑known symptoms of HE. Nevertheless, the link between the direct effect of hyperammonemia and associated gut dysbiosis in the pathogenesis of HE is not well established. Thus, this work aimed to assess motor function in hyperammonemia and gut dysbiosis in mice. Twenty‑eight Swiss mice were distributed into three groups: two‑week and four‑week hyperammonemia groups were fed with an ammonia‑rich diet (20% w/w), and the control group was pair‑fed with a standard diet. Motor performance in the three groups was measured through a battery of motor tests, namely the rotarod, parallel bars, beam walk, and static bars. Microbial analysis was then carried out on the intestine of the studied mice. The result showed motor impairments in both hyperammonemia groups. Qualitative and quantitative microbiological analysis revealed decreased bacterial load, diversity, and ratios of both aerobic and facultative anaerobic bacteria, following two and four weeks of ammonia supplementation. Moreover, the Shannon diversity index revealed a time‑dependent cutback of gut bacterial diversity in a treatment‑time‑dependent manner, with the presence of only Enterobacteriaceae, Streptococcaceae, and Enterococcaceaeat at four weeks. The data showed that ammonia‑induced motor coordination deficits may develop through direct and indirect pathways acting on the gut‑brain axis.

Prenatal alcohol exposure (PAE) refers to fetal exposure to alcohol during pregnancy through placental barrier transfer from maternal blood. The postnatal outcomes of PAE differ among exposed individuals and range from overt (serious) alcohol-related behavioral and neurophysiological impairments to covert (silenced) symptoms. The aims of the present investigation were to assess the postnatal neurobehavioral disturbances, particularly, motor coordination and sensory-motor function in mice with PAE. Female mice with positive vaginal plugs were divided into three groups: group 1: Et + Pyr: received two i.p injections of ethanol (1 g/kg) followed by pyrazole (100 mg/kg). Group 2: Pyr: received an i.p injection of pyrazole (100 mg/kg). Group 3: C: of saline controls received, in equal volume, saline solution (NaCl 0.9%). After birth, mice pups were weighed and subjected to behavioral tests for motor function screening using the motor ambulation test, cliff aversion, surface righting, and negative geotaxis, while at the adult stage, mice were subjected to the open field, rotarod, parallel bars, and static rods tests. Our data show an obvious decrement of body weight from the first post-natal day (P1) and continues over the adult stage. This was accompanied by an obvious impaired sensory-motor function which was maintained even at the adult stage with alteration of the locomotor and coordination abilities. The current data demonstrate the powerful neurotoxic effect of prenatal ethanol exposure on the sensory-motor and coordination functions, leading to suppose possible structural and/or functional neuronal disturbances, particularly the locomotor network.

Parkinson's disease (PD) affects the nervous system of patients in a gender-discriminative way. In regards to the epidemiological observations, amongst the 10 million people worldwide who are living with PD, recent reports have stated 1.5 times the greater incidence in men than in women. What is more, while growing evidence is showing gender as a considerable biological variable, preclinical research on PD has shown tangible explanations of epidemiological observation. Indeed, it has been shown that the symptoms are delayed in women especially because of a high dopamine level in the striatum, possibly due to the activity of estrogens. Thus, in this chapter, the authors present an overview of sexual dimorphism in PD and the possible mechanisms linking the differences observed between men and women in the incidence of PD.

Parkinson's disease (PD) is a progressive neurodegenerative disease representing the most common movement disorder worldwide. It is characterized clinically by its cardinal motor features: bradykinesia, rigidity, postural instability, and resting tremor. The clinical diagnosis of PD is mainly based on the presence of these motor symptoms which differentiate it from the other forms of parkinsonism. However, recently other symptoms known as non-motor symptoms (NMS) are ginning attention because of their negative outcome on PD patients, and they are now included in the clinical diagnosis of the disease. Current lines treatments are generally based on DA replacement and are associated with significant alleviation of motor symptoms and some NMS. However, such treatments have not been shown to decrease or halt the disease progression. Moreover, as the disease progresses, these symptomatic treatments can worsen the disease diagnosis and management.