Carrier Proteins/metabolism; Hypothalamus/metabolism; Intracellular Signaling Peptides and Proteins; Narcolepsy/metabolism; Nerve Degeneration/metabolism; Neurons/metabolism; Neuropeptides/metabolism; Neurotoxins/toxicity; Animals; Enzyme Inhibitors/pharmacology; Excitatory Amino Acid Agonists/metabolism; Excitatory Amino Acid Agonists/toxicity; Hypothalamic Hormones/metabolism; Hypothalamus/pathology; Hypothalamus/physiopathology; In Vitro Techniques; Melanins/metabolism; N-Methylaspartate/pharmacology; N-Methylaspartate/toxicity; Narcolepsy/physiopathology; Nerve Degeneration/chemically induced; Nerve Degeneration/physiopathology; Neurons/drug effects; Neurons/pathology; Neurotoxins/metabolism; Orexin Receptors; Orexins; Pituitary Hormones/metabolism; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases/metabolism; Quinolinic Acid/metabolism; Quinolinic Acid/toxicity; Rats; Rats, Wistar; Receptors, G-Protein-Coupled; Receptors, N-Methyl-D-Aspartate/agonists; Receptors, N-Methyl-D-Aspartate/metabolism; Receptors, Neuropeptide