Primary dissociated neuronal cultures are widely used research tools to investigate of pathological mechanisms and to treat various central and peripheral nervous system problems including trauma and degenerative neuronal diseases. We introduced a protocol that utilizes hippocampal and cortical neurons from embryonic day 17 or 18 mice. We applied appropriate markers (GAP-43 and synaptophysin) to investigate whether neurite outgrowth and synaptogenesis can be distinguished at a particular period of time. GAP-43 was found along the neural processes in a typical granular pattern, and its expression increased proportionally as neurites lengthened during the early in vitro period. Unlike GAP-43, granular immunoreactive patterns of synaptophysin along the neurites were clearly found from day 2 in vitro with relatively high immunoreactive levels. Expression of synaptic markers from cortical neurons reached peak level earlier than that of hippocampal neurons, although neurite outgrowths of hippocampal neurons were faster than those of cortical neurons. The amount of peak synaptic markers expressed was also higher in cortical neurons than that in hippocampal neurons. These results strongly suggest the usefulness of primary cultured neurons from mice embryos for synaptic function and plasticity studies, because of their clear and typical patterns of morphology that establish synapses. Results from this study also suggest the proper amount of time in vitro according to neuronal types (cortical or hippocampal) when utilized in experiments related with synaptogenesis or synaptic activities.
Animals ; Embryonic Structures ; GAP-43 Protein ; Mice ; Neurites ; Neurons ; Peripheral Nervous System ; Plastics ; Synapses ; Synaptophysin

The genetically engineered mice require special husbandry care and are mainly housed in Individually Ventilated Cage (IVC) systems and Static Micro Isolator Cages (SMIC) to minimize the risk for spreading undesirable microorganisms. However, the static micro isolation cage housing like SMIC are being replaced with IVC systems in many facilities due to a number of benefits like a higher density housing in limited space, better protection from biohazards and allergens and decreased work load due to decreased frequency of cage changing required in this system. The purpose of this study was to examine the reproductive performance of genetically engineered mice housed in individually ventilated cages (IVC) and Static Micro Isolator Cages (SMIC). When the B6C3-Tg (APPswe, PSEN1dE9) 85Dbo/Mmjax transgenic mice were housed in these two housing systems, the number of litters per dam, number of pups born per dam and number of pups weaned per dam were found to be slightly higher in the IVC as compared to the SMIC but the difference was not significant (P<0.05). In case of Growth Associated Protein 43 (GAP-43) knockout mice, the number of litters born per dam and the number of pups born per dam were marginally higher in the IVC as compared to those housed in SMIC but the difference was not significant (P<0.05). Only the number of pups weaned per dam were found to be significantly higher as compared to those housed in the SMIC system at P<0.05.
Allergens ; Animals ; GAP-43 Protein ; Hazardous Substances ; Housing* ; Mice* ; Mice, Knockout ; Mice, Transgenic

Although growth associated protein-43 (GAP-43) is known to play a significant role in the regulation of axonal growth and the formation of new neuronal connections in the hippocampus, there is only a few studies on the effects of acute stress on GAP-43 mRNA expression in the hippocampus. Moreover, the effects of repeated citalopram treatment on chronic mild stress (CMS)-induced changes in GAP-43 mRNA expression in the hippocampus have not been explored before. To explore this question, male rats were exposed to acute immobilization stress or CMS. Also, citalopram was given prior to stress everyday during CMS procedures. Acute immobilization stress significantly increased GAP-43 mRNA expression in all subfields of the hippocampus, while CMS significantly decreased GAP-43 mRNA expression in the dentate granule cell layer (GCL). Repeated citalopram treatment decreased GAP-43 mRNA expression in the GCL compared with unstressed controls, but this decrease was not further potentiated by CMS exposure. Similar decreases in GAP-43 mRNA expression were observed in CA1, CA3 and CA4 areas of the hippocampus only after repeated citalopram treatment in CMS-exposed rats. This result indicates that GAP-43 mRNA expression in the hippocampus may differently respond to acute and chronic stress, and that repeated citalopram treatment does not change CMS-induced decreases in GAP-43 mRNA expression in the GCL.
Animals ; Axons ; Citalopram ; GAP-43 Protein ; Hippocampus ; Humans ; Immobilization ; Male ; Neurons ; Rats ; RNA, Messenger

OBJECTIVE: To verify the effect of low energy laser irradiation (LELI) on the regeneration of injured sciatic nerve of the rat by showing the functional improvement and the elevated immunoreactivities (IRs) of growth-associated protein 43 (GAP-43). METHOD: Twenty rats, which had standardized compression injuries to the sciatic nerves, received the calculated LELI therapy immediately after the nerve injury and four consecutive days. The functional status was evaluated by sciatic functional index (SFI), and GAP-43-IRs was evaluated by immunohistochemistry and RT-PCR. RESULTS: The SFI was recovered in LELI rats faster than in the control group. Although expression of GAP-43 in the injured sciatic nerve was increased both in the LELI and control groups, the intensities of GAP-43-IRs were much greater in LELI treated group at 1 and 3 weeks after nerve injury. Both SFI and GAP-43-IRs reached the same level at 5 weeks after the nerve injury. CONCLUSION: LELI enhanced the neural regeneration after experimentally induced sciatic nerve injury at the early stage of recovery. Considering the effect of LELI on nerve regeneration was not fully explained until now, this study could suggest the meaningful explanation on the mechanism of LELI effectiveness on neural regeneration.
Animals ; GAP-43 Protein ; Immunohistochemistry ; Nerve Regeneration ; Peripheral Nerve Injuries ; Rats* ; Regeneration* ; Sciatic Nerve*

OBJECTIVETo investigate whether there is neogenesis of myelin sheath and neuron after transplantation of Schwann cells into cerebral hemorrhage lesion.

METHODSSchwann cells were expanded, labeled with BrdU in vitro and transplanted into rat cerebral hemorrhage with blood extracted from femoral artery and then injected into the basal nuclei. Double immunohistochemistry staining and electron microscopy were used to detect the expression of BrdU/MBP and BrdU/GAP-43 and remyelination.

RESULTSBrdU/MBP double positive cells could be seen at 1 week up to 16 weeks after transplantation of Schwann cells. Thin remyelination was observed under electron microscope. GAP-43 positive cells appeared after 12 weeks and were found more in Hippocamp.

CONCLUSIONSGrafted Schwann cells participate in remyelination and promoter nerve restore in rat cerebral hemorrhage.

Animals ; Cerebral Hemorrhage ; metabolism ; therapy ; GAP-43 Protein ; metabolism ; Rats ; Rats, Wistar ; Schwann Cells ; metabolism ; transplantation ; Sciatic Nerve ; cytology ; embryology

OBJECTIVE: To observe the effect of moxibustion at "Huantiao" (GB 30) on the expression of growth-associated protein-43 (GAP-43) in the sciatic nerve trunk and ventral horn of spinal cord (L METHODS: A total of 48 healthy male SD rats were randomly divided into a normal group, a sham operation group, a model group and a moxibustion group, 12 rats in each group. The rat model of primary sciatic pain was established by chronic constriction injury (CCI) of the sciatic nerve in the model group and the moxibustion group. On the 8th day of the experiment, moxibustion was adopted at "Huantiao" (GB 30) in the moxibustion group for 5-10 min, once a day for 14 consecutive days. Sciatic nerve function index (SFI) was measured and compared in each group at day 1, 7, 14 and 21. On the 21st day of the experiment, HE staining was used to observe the morphology of ventral horn of rat spinal cord and sciatic nerve trunk. Immunohistochemical method and real-time PCR were used to detect mRNA and protein expressions of GAP-43 in the spinal cord and sciatic nerve trunk of rats. RESULTS: On day 7, 14 and 21, there was no statistical difference in SFI between the sham operation group and the normal group ( CONCLUSION Moxibustion at "Huantiao" (GB 30) could improve the sciatic nerve function in rats with primary sciatica and its mechanism may be related to improving the expression of GAP-43 and enhancing the self-repair ability of the sciatic nerve after injury.
Animals ; Electroacupuncture ; GAP-43 Protein/genetics* ; Male ; Moxibustion ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; Sciatica/therapy* ; Spinal Cord

Caveolin-1 (Cav-1) is a marker protein for caveolae, and acts as scaffolding protein to regulate the activities of signaling molecules. Previous studies indicate that Cav-1 mainly locates at the base of axonal and dendritic terminals of mouse primary hippocampal neurons and plays an active role in the regulation of injury-induced synaptic and terminal remodeling in central nervous system. The aim of this study was to identify the expression profile of Cav-1 protein in the brains of rats at different ages and to investigate the role of Cav-1 in Y-maze bright-dark discrimination learning (BDL). Firstly, the expressions of Cav-1 in the brains of young (1-month), adult (3-month) and aged (22-month) rats were observed by Western blot. Higher expression in the hippocampus and lower expression in the cortex were shown in the adult rats. It was also found that the score of BDL was related with the expression level of Cav-1. Secondly, using open-field test for spontaneous locomotor activities (SLA) and BDL, the role of Cav-1 in the learning and memory was observed. Compared with that in the control adult group, the Cav-1 protein expression in the hippocampus and prefrontal cortex of Y-maze trained adult rats significantly increased, while no marked changes in the cerebellum. These results suggest that Cav-1 protein is involved in BDL and plays an important role in the plasticity of central nervous system.
Age Factors ; Animals ; Brain Chemistry ; Caveolin 1 ; analysis ; physiology ; Discrimination Learning ; GAP-43 Protein ; analysis ; Male ; Maze Learning ; Rats ; Rats, Sprague-Dawley ; Synaptophysin ; analysis

Animals ; GAP-43 Protein ; metabolism ; Ganglia, Spinal ; drug effects ; metabolism ; Nerve Block ; Rats ; Rats, Wistar ; Sciatic Nerve ; drug effects ; injuries ; Tetrodotoxin ; pharmacology

OBJECTIVETo explore the ability of grafted Schwann cells to promote restore of injured neurons in rat.

METHODSSchwann cells labeled by BrdU in vitro transplanted into rat middle brain area prior to injure with electric needle stimulus. Immunohistochemistry and image analyzer were used to investigate the expression of BrdU and GAP-43 as well as quantitative analysis respectively.

RESULTSBrdU positive cells could be identified for up to 8 months and the number increased about 15%, which mainly migrated toward injured ipsilateral cortex. The GAP-43 expression reached its peak one month after transplantation and was significant compared with control group (P < 0.05).

CONCLUSIONThe transplantation of Schwann cells could promote the restoration of injured neurons.

Animals ; Cell Transplantation ; GAP-43 Protein ; analysis ; Immunohistochemistry ; Mesencephalon ; injuries ; metabolism ; surgery ; Rats ; Rats, Wistar ; Schwann Cells ; metabolism ; transplantation ; Time Factors

OBJECTIVETo explore the effect of Shenxiong Huayu Capsule (SHC) on the cerebral ischemia-reperfusion (IR) injury and the expression of growth associated protein 43 (GAP43) after total cerebral IR in the hippocampal CA1 region of rats.

METHODSTotally 100 male adult SD rats were randomly divided into five groups, i.e., the control group, the model group, the group A (by taking SHC once daily), the group B (by taking SHC twice daily), and the group C (by taking SHC thrice daily), 20 in each group. The total IR model was prepared by improved Pulsinelli's 4-vessel occlusion method. Morphological changes of the hippocampal CA1 region were observed by HE staining at day 1, 3, 7, and 14. The expression of GAP43 in the hippocampal CA1 region was detected using immunohistochemical assay at day 1, 3, 7, and 14. Meanwhile, the behavioral score was determined. The expression of GAP43 in the hippocampal CA1 region was detected using Western blot at day 14.

RESULTSCompared with the control group, the expression of GAP43 increased in the model group, the behavioral score was elevated, degenerated neurons increased, and survival neurons decreased in the model group (all P < 0.05). Compared with the model group, the expression of GAP-43 increased (with the most significant difference seen in the group C, P < 0.01), the behavioral score significantly decreased, degenerated neurons decreased, and survival neurons increased in each HSC group (all P < 0.05). Survival neurons obviously increased at day 14, of which, most number of survival neurons and highest contents of GAP43 protein could be seen in the group C, showing statistical difference when compared with those of the group A and the group B (P < 0.01).

CONCLUSIONSHC had protective effect on total cerebral IR in the hippocampal CA1, which might be associated with increased expression of GAP43.

Animals ; Brain Ischemia ; metabolism ; CA1 Region, Hippocampal ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; GAP-43 Protein ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; metabolism