Intramuscular Injection of BOTOX® Boosts Learning and Memory in Adult Mice in Association with Enriched Circulation of Platelets and Enhanced Density of Pyramidal Neurons in the Hippocampus

Rivastigmine ameliorates botulinum-induced hippocampal damage and spatial memory impairment in male rats

Botulinum toxin (Botox) is widely used in beauty industry and its long-term consequences can be a matter of concern. The hippocampal cholinergic system plays a significant role in memory and learning that could be affected by Botulinum toxin. However, to date, the effect of Botox on memory system has been controversial. This survey aimed to examine the effects of Botox on spatial memory, and biochemical and histological parameters of the hippocampus in male rats by using Rivastigmine (R) as a cholinesterase inhibitor that is more selective for the central nervous system (CNS). Thirty-five male Wistar rats (200-250 g) were distributed into seven groups: Sham, Botox A (3, 6, and 15 IU intramascularly) and Botox A (3, 6, and 15 IU) plus Rivastigmine (1 mg/kg intraperitoneally). Spatial memory was assessed in the Morris Water Maze (MWM) 4 weeks later. Moreover, the hippocampal tissue was removed for histopathological and biochemical analyses. Botox significantly impaired memory performance in MWM by increasing escape latency and swim distance and decreasing the time spent in the target zone. Furthermore, in the Botox groups, the level of acetylcholine decreased, while the level of the acetylcholinesterase enzyme increased significantly in the hippocampus. Also, local lesions were observed in the form of degeneration and loss of pyramidal neurons, as well as a decrease in the volume and shrinkage of the cell body and an increase in microglia in the damaged area. Rivastigmine administration alleviated biochemical and histological parameters and partially ameliorated Botox-induced impairments. In summary, rivastigmine could be a suitable protective approach for side effects of Botox in the hippocampus.

A Mild Dose of Aspirin Promotes Hippocampal Neurogenesis and Working Memory in Experimental Ageing Mice

Aspirin has been reported to prevent memory decline in the elderly population. Adult neurogenesis in the hippocampus has been recognized as an underlying basis of learning and memory. This study investigated the effect of aspirin on spatial memory in correlation with the regulation of hippocampal neurogenesis and microglia in the brains of ageing experimental mice. Results from the novel object recognition (NOR) test, Morris water maze (MWM), and cued radial arm maze (cued RAM) revealed that aspirin treatment enhances working memory in experimental mice. Further, the co-immunohistochemical assessments on the brain sections indicated an increased number of doublecortin (DCX)-positive immature neurons and bromodeoxyuridine (BrdU)/neuronal nuclei (NeuN) double-positive newly generated neurons in the hippocampi of mice in the aspirin-treated group compared to the control group. Moreover, a reduced number of ionized calcium-binding adaptor molecule (Iba)-1-positive microglial cells was evident in the hippocampus of aspirin-treated animals. Recently, enhanced activity of acetylcholinesterase (AChE) in circulation has been identified as an indicative biomarker of dementia. The biochemical assessment in the blood of aspirin-treated mice showed decreased activity of AChE in comparison with that of the control group. Results from this study revealed that aspirin facilitates hippocampal neurogenesis which might be linked to enhanced working memory.

Efficiency of botulinum toxin injection into the arm on postural balance and gait after stroke

The purpose of this study was to clarify the association between improvement of spasticity in hemiplegic patient's upper extremity with Botulinum toxin injection and improvement in postural balance and gait function. For this prospective cohort study, sixteen hemiplegic stroke patients with upper extremity spasticity were recruited. The plantar pressure with gait parameters, postural balance parameters, Modified Ashworth Scale, and Modified Tardieu Scale were evaluated before, 3 weeks and 3 months after Botulinum toxin A (BTxA) injection. Spasticity of hemiplegic upper extremity before, and after BTxA injection were significantly changed. Plantar pressure overload in affected side was reduced after BTxA injection. The mean X-speed and the horizontal distance decreased in postural balance analysis with eyes-opened test. Improvement in hemiplegic upper extremity spasticity showed positive correlation with gait parameters. In addition, improvement in hemiplegic upper extremity spasticity was positively correlated with change in balance parameters in postural balance analysis with eyes-closed and dynamic tests. This study focused on the effect of stroke patient's hemiplegic upper extremity spasticity on their gait and balance parameters and identified that the BTxA injection on hemiplegic patient's spastic upper extremity improve postural balance and gait function.

Ranitidine Alleviates Anxiety-like Behaviors and Improves the Density of Pyramidal Neurons upon Deactivation of Microglia in the CA3 Region of the Hippocampus in a Cysteamine HCl-Induced Mouse Model of Gastrointestinal Disorder

Elevated levels of histamine cause over-secretion of gastric hydrochloric acid (HCl), leading to gastrointestinal (GI) disorders and anxiety. Ranitidine is an antihistamine drug widely used in the management of GI disorders, as it works by blocking the histamine-2 receptors in parietal cells, thereby reducing the production of HCl in the stomach. While some reports indicate the neuroprotective effects of ranitidine, its role against GI disorder-related anxiety remains unclear. Therefore, we investigated the effect of ranitidine against anxiety-related behaviors in association with changes in neuronal density in the hippocampal cornu ammonis (CA)-3 region of cysteamine hydrochloride-induced mouse model of GI disorder. Results obtained from the open field test (OFT), light and dark box test (LDBT), and elevated plus maze (EPM) test revealed that ranitidine treatment reduces anxiety-like behaviors in experimental animals. Nissl staining and immunohistochemical assessment of ionized calcium-binding adapter molecule (Iba)-1 positive microglia in cryosectioned brains indicated enhanced density of pyramidal neurons and reduced activation of microglia in the hippocampal CA-3 region of brains of ranitidine-treated experimental mice. Therefore, this study suggests that ranitidine mediates anxiolytic effects, which can be translated to establish a pharmacological regime to ameliorate anxiety-related symptoms in humans.

Single injection of very mild dose botulinum toxin in the vastus lateralis improves testicular spermatogenesis and sperm motility in ageing experimental mice

Background

Botulinum toxin (BoNT) is a widely used therapeutic agent that blocks the excessive release of acetylcholine at the neuromuscular junction. Previously, repeated intracremasteric injections and slight overdose of BoNT have been reported to induce adverse effects in the testicular parameter of experimental rodents. However, a mild dose of BoNT is highly beneficial against skin ageing, neuromuscular deficits, overactive urinary bladder problems, testicular pain and erectile dysfunctions. Considering the facts, the possible therapeutic benefits of BoNT on the testis might be achieved at a very minimal dosage and via a distal route of action. Therefore, we revisited the effect of BoNT, but with a trace amount injected into the vastus lateralis of the thigh muscle, and analyzed histological parameters of the testis, levels of key antioxidants and sperm parameters in ageing experimental mice.

Results

Experimental animals injected with 1 U/kg bodyweight of BoNT showed enhanced spermatogenesis in association with increased activities of key antioxidants in the testis, leading to enhanced amount of the total sperm count and progressive motility.

Conclusions

This study signifies that a mild intramuscular dose of BoNT can be considered as a potent treatment strategy to manage and prevent male infertility.

Botulinum Neurotoxins in Central Nervous System: An Overview from Animal Models to Human Therapy

Botulinum neurotoxins (BoNTs) are potent inhibitors of synaptic vesicle fusion and transmitter release. The natural target of BoNTs is the peripheral neuromuscular junction (NMJ) where, by blocking the release of acetylcholine (ACh), they functionally denervate muscles and alter muscle tone. This leads them to be an excellent drug for the therapy of muscle hyperactivity disorders, such as dystonia, spasticity, and many other movement disorders. BoNTs are also effective in inhibiting both the release of ACh at sites other than NMJ and the release of neurotransmitters other than ACh. Furthermore, much evidence shows that BoNTs can act not only on the peripheral nervous system (PNS), but also on the central nervous system (CNS). Under this view, central changes may result either from sensory input from the PNS, from retrograde transport of BoNTs, or from direct injection of BoNTs into the CNS. The aim of this review is to give an update on available data, both from animal models or human studies, which suggest or confirm central alterations induced by peripheral or central BoNTs treatment. The data will be discussed with particular attention to the possible therapeutic applications to pathological conditions and degenerative diseases of the CNS.

BOTOX® counteracts the innate anxiety-related behaviours in correlation with increased activities of key antioxidant enzymes in the hippocampus of ageing experimental mice

Cholinergic crisis and oxidative stress in the hippocampus of the brain have been known to induce anxiety disorders upon ageing. BOTOX® is a widely used therapeutic form of botulinum neurotoxin that acts by inhibiting the release of acetylcholine (ACh) from the nerve terminals at the neuromuscular junction. BOTOX® can migrate from the muscle to the brain through retrograde axonal transport and modulate neuroplasticity. While a mild dose of BOTOX® has been used to manage various neurological deficits and psychiatric complications including depression, the efficacy and experimental evidence for its anxiolytic effects and antioxidant properties remain limited. In this study, we have investigated the effect of BOTOX® on the innate anxiety-like behaviours in ageing mice upon exposure to different behavioural paradigms like open field test, elevated plus maze and light-dark box test, and estimated the enzymatic activities of key antioxidants in the hippocampus. Results revealed that animals injected with a mild intramuscular dosage of BOTOX® showed reduced level of innate anxiety-related symptoms and increased activities of hippocampal antioxidant enzymes compared to the control group. This study strongly supports that BOTOX® could be implemented to prevent or treat anxiety and hippocampal oxidative stress resulting from ageing, emotional and mood disorders.