Biomaterial Database

Primary afferent depolarization in the in vitro frog olfactory bulb. 1981

C E Jahr, and R A Nicoll

1. Experiments on the frog olfactory bulb have been performed in vitro in order to determine whether primary afferent transmission is modified by presynaptic inhibition.2. Stimulation of the olfactory nerve resulted in a prolonged depolarization of the olfactory nerve as recorded across a sucrose gap. Unstimulated olfactory nerve fibres adjacent to the stimulated fibres were also depolarized.3. An excitability increase of the olfactory nerve terminals was found that lasted the entire duration of the olfactory nerve depolarization, indicating that the terminals themselves were depolarized. Both the olfactory nerve depolarization and the excitability increase were blocked by cobalt and manganese ions.4. Low concentrations of glutamate were found to produce a substantial depolarization of the olfactory nerve. Although gamma-aminobutyric acid (GABA) also elicited a depolarization of the olfactory nerve, picrotoxin, a GABA antagonist, did not reduce the stimulus-evoked olfactory nerve depolarization.5. Recording with potassium-sensitive electrodes in the olfactory nerve terminal region demonstrated an increase in extracellular potassium with the same rise time and duration as the olfactory nerve depolarization. Cobalt and manganese blocked the potassium increase and the olfactory nerve depolarization without affecting the presynaptic action potential.6. The focally recorded extracellular current resulting from orthodromic synaptic excitation of the secondary olfactory relay neurones was blocked at short intervals by paired stimulation and decreased for the duration of the olfactory nerve depolarization. This suggests a decreased release of transmitter from the olfactory nerve terminals.7. The possible role of potassium and/or a neurotransmitter in generating the olfactory nerve depolarization and inhibition is discussed.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009433	Neural Inhibition	The function of opposing or restraining the excitation of neurons or their target excitable cells.	Inhibition, Neural
D009475	Neurons, Afferent	Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.	Afferent Neurons,Afferent Neuron,Neuron, Afferent
D009832	Olfactory Nerve	The 1st cranial nerve. The olfactory nerve conveys the sense of smell. It is formed by the axons of OLFACTORY RECEPTOR NEURONS which project from the olfactory epithelium (in the nasal epithelium) to the OLFACTORY BULB.	Cranial Nerve I,First Cranial Nerve,Nervus Olfactorius,Fila Olfactoria,Olfactory Fila,Cranial Nerve Is,Cranial Nerve, First,Cranial Nerves, First,First Cranial Nerves,Nerve I, Cranial,Nerve Is, Cranial,Nerve, First Cranial,Nerve, Olfactory,Nerves, Olfactory,Olfactory Nerves
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D011892	Rana catesbeiana	A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.	Bullfrog,Bullfrogs,Rana catesbeianas,catesbeiana, Rana
D005071	Evoked Potentials	Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.	Event Related Potential,Event-Related Potentials,Evoked Potential,N100 Evoked Potential,P50 Evoked Potential,N1 Wave,N100 Evoked Potentials,N2 Wave,N200 Evoked Potentials,N3 Wave,N300 Evoked Potentials,N4 Wave,N400 Evoked Potentials,P2 Wave,P200 Evoked Potentials,P50 Evoked Potentials,P50 Wave,P600 Evoked Potentials,Potentials, Event-Related,Event Related Potentials,Event-Related Potential,Evoked Potential, N100,Evoked Potential, N200,Evoked Potential, N300,Evoked Potential, N400,Evoked Potential, P200,Evoked Potential, P50,Evoked Potential, P600,Evoked Potentials, N100,Evoked Potentials, N200,Evoked Potentials, N300,Evoked Potentials, N400,Evoked Potentials, P200,Evoked Potentials, P50,Evoked Potentials, P600,N1 Waves,N2 Waves,N200 Evoked Potential,N3 Waves,N300 Evoked Potential,N4 Waves,N400 Evoked Potential,P2 Waves,P200 Evoked Potential,P50 Waves,P600 Evoked Potential,Potential, Event Related,Potential, Event-Related,Potential, Evoked,Potentials, Event Related,Potentials, Evoked,Potentials, N400 Evoked,Related Potential, Event,Related Potentials, Event,Wave, N1,Wave, N2,Wave, N3,Wave, N4,Wave, P2,Wave, P50,Waves, N1,Waves, N2,Waves, N3,Waves, N4,Waves, P2,Waves, P50
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013569	Synapses	Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.	Synapse
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In