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N-Phthalimido β-amino acid derivatives, 3-phthalimido-3(2-hydroxyphenyl) propanoic acid (P2HPA) and 3-phthalimido-3(2-nitrophenyl) propanoic acid (P2NPA) with new series of diand triorganotin(IV) complexes (1-12) have been designed and synthesized. All the ligands and organotin(IV) complexes were characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H, 13C, 119Sn) spectroscopy and electron ionization mass spectrometry (EI-MS). Synthesized ligands and complexes were screened to determine the antibacterial activity and results showed that the triorganotin(IV) complexes have better activity compared to diorganotin(IV) complexes and ligands. In addition, molecular docking analysis of ligands on the catalytic pocket of sortase A (PDB ID 1T2W) showed that the ligands can bind the active amino acid residues in the pocket. The antioxidant activity was also performed by the DPPH (1,1-diphenyl-2-picrylhydrazyl radical) method and complexes showed better results than ligands. The compounds were also tested in vivo to determine the hypoglycemic activities on different groups of alloxan induced diabetic rabbits. The complexes (1-6) were found better hypoglycemic agents as they stabilized the glucose level to about 175-105 mg dL-1 as compared to ligand P2HPA.

This paper describes research methods to investigate the development of synaptic connections between transplanted GABAergic interneurons and endogenous neurons in the adult mouse hippocampus. Our protocol highlights methods for retroviral labeling adult-born GCs, one of the few cell types in the adult brain to be continuously renewed throughout life. By precise targeting of the retrovirus, labeling of adult-born GCs can be combined with optogenetic stimulation of the transplanted cells and electrophysiology in brain slices, to test whether the GABAergic interneurons integrate and establish inhibitory synaptic connections with host brain neurons. Modifications to adult neurogenesis are an important contributing factor in the development and severity of TLE and seizures. When combined with retroviral labeling, the approaches we describe in this chapter can be used to determine whether transplantation modifies the process of adult neurogenesis or other properties of the hippocampus. These approaches are helping to define parameters for potential cell replacement therapies to be used in patients with intractable seizure disorders.

This paper describes research methods to investigate the development of synaptic connections between transplanted GABAergic interneurons and endogenous neurons in the adult mouse hippocampus. Our protocol highlights methods for retroviral labeling adult-born GCs, one of the few cell types in the adult brain to be continuously renewed throughout life. By precise targeting of the retrovirus, labeling of adult-born GCs can be combined with optogenetic stimulation of the transplanted cells and electrophysiology in brain slices, to test whether the GABAergic interneurons integrate and establish inhibitory synaptic connections with host brain neurons. Modifications to adult neurogenesis are an important contributing factor in the development and severity of TLE and seizures. When combined with retroviral labeling, the approaches we describe in this chapter can be used to determine whether transplantation modifies the process of adult neurogenesis or other properties of the hippocampus. These approaches are helping to define parameters for potential cell replacement therapies to be used in patients with intractable seizure disorders.

In the pilocarpine model of temporal lobe epilepsy (TLE) in rodents, systemic injections of pilocarpine induce continuous, prolonged limbic seizures, a condition termed "Status Epilepticus" (SE). With appropriate doses, many inbred strains of mice show behavioral seizures within an hour after pilocarpine is injected. With the behavioral scoring system based on a modification of the original Racine scale, one can monitor the seizures behaviorally, as they develop into more prolonged seizures and SE. SE is typically associated with damage to subsets of hippocampal neurons and other structural changes in the hippocampus and generally subsides on its own. However, more precise control of the duration of SE is commonly achieved by injecting a benzodiazepine into the mouse 1 to 3 h after the onset of SE to suppress the seizures. Several days following pilocarpine-induced SE, electrographic and behavioral seizures begin to occur spontaneously. The goal of this protocol is to reliably generate mice that develop spontaneous recurrent seizures (SRS) and show the typical neuropathological changes in the brain characteristic of severe human mesial temporal lobe epilepsy (mTLE), without high mortality. To reduce mortality, multiple subthreshold injections of pilocarpine are administered, which increases the percentage of mice developing SE without concomitant mortality. Precise control of the duration of SE (1 or 3 h) is achieved by suppressing SE with the benzodiazepine Midazolam (Versed). We have found that this protocol is an efficient means for generating mice that subsequently develop characteristics of human mTLE including high-frequency interictal spike and wave activity and SRS. In addition, we and others have shown that this protocol produces mice that show excitotoxic cell death of subsets of hippocampal GABAergic interneurons, particularly in the dentate gyrus and compensatory sprouting of excitatory projections from dentate granule cells (mossy fiber sprouting). Aspects of this protocol have been described in several of our previous publications.

The dentate gyrus (DG) is a region of the adult rodent brain that undergoes continuous neurogenesis. Seizures and loss or dysfunction of GABAergic synapses onto adult-born dentate granule cells (GCs) alter their dendritic growth and migration, resulting in dysmorphic and hyperexcitable GCs. Additionally, transplants of fetal GABAergic interneurons in the DG of mice with temporal lobe epilepsy (TLE) result in seizure suppression, but it is unknown whether increasing interneurons with these transplants restores GABAergic innervation to adult-born GCs. Here, we address this question by birth-dating GCs with retrovirus at different times up to 12 weeks after pilocarpine-induced TLE in adult mice. Channelrhodopsin 2 (ChR2)-enhanced yellow fluorescent protein (EYFP)-expressing medial-ganglionic eminence (MGE)-derived GABAergic interneurons from embryonic day (E)13.5 mouse embryos were transplanted into the DG of the TLE mice and GCs with transplant-derived inhibitory post-synaptic currents (IPSCs) were identified by patch-clamp electrophysiology and optogenetic interrogation. Putative synaptic sites between GCs and GABAergic transplants were also confirmed by intracellular biocytin staining, immunohistochemistry, and confocal imaging. 3D reconstructions of dendritic arbors and quantitative morphometric analyses were carried out in >150 adult-born GCs. GABAergic inputs from transplanted interneurons correlated with markedly shorter GC dendrites, compared to GCs that were not innervated by the transplants. Moreover, these effects were confined to distal dendritic branches and a short time window of six to eight weeks. The effects were independent of seizures as they were also observed in naïve mice with MGE transplants. These findings are consistent with the hypothesis that increased inhibitory currents over a smaller dendritic arbor in adult-born GCs may reduce their excitability and lead to seizure suppression.

Three novel derivatives of (E)-N′-nitrobenzylidene-benzenesulfonohydrazide (NBBSH) were synthesized by a condensation method from nitrobenzaldehyde and benzenesulfonylhydrazine reactants in low to moderate yields, which crystallized in methanol, acetone, ethyl acetate, and ethanol. NBBSH derivatives were totally characterized using various spectroscopic techniques, such as Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, proton nuclear magnetic resonance spectroscopy (1H NMR), and carbon-13 nuclear magnetic resonance (13C NMR) spectroscopy. The molecular structure of the NBBSH derivates was confirmed by the single crystal X-ray diffraction method and used for potential detection of a selective heavy metal ion, mercury (Hg2+), by a reliable I–V method. A thin coating of NBBSH derivatives was deposited on a glassy carbon electrode (surface area = 0.0316 cm2) with a binder (nafion) coating to modify a sensitive and selective Hg2+ sensor with a short response time in phosphate buffer. The modified cationic sensor exhibited enhanced chemical performances, such as higher sensitivity, linear dynamic range, limit of detection (LOD), reproducibility, and long-term stability toward Hg2+. The calibration curve was found to be linear over a wide range of Hg2+ concentrations (100.0 pM–100.0 mM). The sensitivity and LOD were considered to be ∼949.0 pA μM–1cm–2 and 10.0 ± 1.0 pM (S/N = 3), respectively. The sensor was applied to the selective measurement of Hg2+ in spiked water samples to give acceptable and satisfactory results.