Disease relevance of TECTA

• When HRP is injected into the optic tecta of embryonic or newly hatched chicks, the ganglion cells in the contralateral retina can be successfully dissociated into culture and identified at any time by appropriate histochemical staining [1].
• By means of light and electron microscopy we have studied the effect of interferon beta-1a (IFNbeta-1a) in the optic tecta of 20-day-old chick embryos under normal conditions and after exposure to lipopolysaccharide (LPS) which mimics the blood-brain barrier (BBB) disruption in meningoencephalitis [2].

High impact information on TECTA

• The 8D9 antigen, a cell surface protein isolated from chicken brain that is related to the L1 class of cell adhesion molecules, is shown to contain an activity that promotes the attachment of neurons and the outgrowth of neurites from chicken tecta and mouse cerebellum [3].
• Immunoelectron microscopy of normal tecta demonstrated the presence of N-cadherin in the synaptic cleft, suggesting a role for this molecule in synaptic maintenance [4].
• We have investigated how neurons in the optic tecta of embryonic day 16 chick embryos depend for survival on their afferents from the retina [5].
• To examine the positional value of the tectal primordium, we produced ectopic tecta in the diencephalon by transplanting a part of the mesencephalic alar plate heterotopically [6].
• When excised optic tecta are exposed to cationized ferritin for various times, ferritin micelles appear sequentially in coated pits, coated vesicles, smooth vesicles, vacuoles, and then in stacked and single disks, including some of those contacting the plasmalemma [7].

Biological context of TECTA

• Effects of enucleation on high-affinity binding sites in chick optic tecta [8].
• Anterograde labeling of retinal axons entering these optic tecta revealed abnormal axonal phenotypes [9].

Anatomical context of TECTA

• The presence of radiolabeled NCAM in the optic nerves and contralateral tecta was detected by specific immunoadsorption to a monoclonal antibody [10].
• This asymmetry is manifested as a difference between the two halves of the forebrain and the tecta [11].
• In cultures prepared from E10 tecta, both stain a filamentous meshwork in glial cells but not in neurons [12].
• After 48 hours, the ultrastructure of superficial tectal layers was analyzed and compared with samples from control tecta injected with cytochrome C. NT-3 increased the number of synapses, synaptic vesicles/profile, synaptic vesicle densities, the number of docked vesicles, and the length of the synaptic profile [13].
• Temporal RGC growth cones collapsed and retracted with a high probability from neuronal cells dissociated from posterior tecta, indicating that repellent components were enriched on posterior target neurons [14].

Associations of TECTA with chemical compounds

• A new series of indole melatonin analogues, bearing the amido ethyl side chain attached at the N-1 position of the indole nucleus, were synthesized and tested for their affinity for the melatonin receptor isolated from quail optic tecta in a series of in vitro ligand-binding experiments using 2-[125I]iodomelatonin as the labeled ligand [15].
• The cyclic AMP increase elicited by 2-chloroadenosine was greatly reduced in tecta from 20-day-old embryos and 2-day-old chicks [16].
• When tecta from 18-day-old embryos were incubated with the phosphodiesterase inhibitor IBMX and RO 20-1724, the cyclic AMP level increased from 39.2 to 73.3 and 285.5 pmol/mg protein, respectively [16].
• The putative transmitters glutamate and glycine and the neurotransmitter analogs isoproterenol and carbachol had no stimulatory effect on the cyclic AMP accumulation of tecta from 10- and 17-day-old embryos [16].
• Fourteen days after the injection of kainic acid, during which the control tecta grow appreciably, all the superficial layers of the tectum contralateral to the kainic acid-lesioned eye, especially layers IIc and IId, were smaller than in controls, and did not differ in size from those seen in tecta contralateral to cut optic nerves [17].

Analytical, diagnostic and therapeutic context of TECTA

• DiI was applied to the optic nerves or tecta in fixed chick embryos (Embryonic Days 4-10); 1-2 months later the tissues were dissected and examined as whole mounts or vibratome sections using fluorescent and confocal microscopy [18].
• One to 5 days after transplantation the tecta were fixed and transplants that issued fibers were examined on tectal whole-mounts or were sectioned and viewed with a fluorescence microscope [19].
• Comparison of the number of synapses per unit area in control versus experimental tecta, after unilateral eye enucleations of E3, indicates that the presynaptic terminals of some synapses present at E8 are of retinal origin [20].
• Monosialogangliosides were extracted from the retinas and optic tecta of chick embryos at 6-12 days of incubation, and analyzed by high-performance liquid chromatography [21].

References