Лекция 1 7 ОРГАНЫ ОЩУЩЕНИЯ

1. Лекция 17 ОРГАНЫ ОЩУЩЕНИЯ

2. Осязание

3. Клетки коротко- и длинно-дистантных сенсорных рецепторов

4. Рецепторы растяжения ракообразных (long sensory receptor)

5. Сенсорный рецептор веретёнообразной мышцы млекопитающего

6. (a) Gentle touch 1 fires slowly 2 silent Сигнальный стимул интенсивности 1 2 (b) Moderate pressure 1 fires more rapidly 2 silent 1 2 (c) Strong pressure 1 fires very rapidly 2 1 2 fires slowly

7. Рефлекс поверхностного болевого ощущения sensation relayed to the brain dorsal root REFLEX ARC receptor stimulus effector ventral root

8. Механорецепторы кожи

9. Sensory Nerve Endings in Skin

10. Nerve Endings in The Skin

11. Сенсорная система осязания

12. Рецепторы осязания и латеральное ингибирование

13. Органы обоняния, слуха и вкуса

14. Схематическое представление морфогенеза и дифференцировки эктодермы в различные черепные плакоды у позвоночных (Schlosser, 2006)

15. Органы вкуса и запаха

16. Обоняние Способность ощущать запахи обязана существованию обонятельных рецепторов

17. Развитие обонятельных органов

18. Обонятельные рецепторы • Although the human sense of smell is feeble compared to that of many animals, it is still very acute. We can recognise thousands of different smells, and we are able to detect odours even in infinitesimal quantities. • Our smelling function is carried out by two small odour-detecting patches – made up of about five or six million yellowish cells – high up in the nasal passages. • For comparison, a rabbit has 100 million of these olfactory receptors, and a dog 220 million. Humans are nonetheless capable of detecting certain substances in dilutions of less than one part in several billion parts of air.

19. olfactory structure of brain olfactory epithelium nasal cavity association neurons bone olfactory receptors air with odor molecules mucus layer olfactory dendrites nasal cavity

20. Competence, specification and commitment to an olfactoryplacode fate Sujata Bhattacharyya and Marianne Bronner-Fraser, Development 135, 4165-4177 (2008) The nasal placode shares a common origin with other sensory placodes within a preplacodal domain at the cranial neural plateborder. However, little is known about early events in nasal placode development as it segregates from prospective lens, neuraltube and epidermis. Dlx3, Dlx5, Pax6 and the pan-neuronal marker Hu serve as molecular labels to follow the maturation ofolfactory precursors over time. When competence to form olfactory placode was tested by grafting ectoderm from different axiallevels to the anterior neural fold, we found that competence is initially broad for head, but not trunk, ectoderm and declinesrapidly with time. Isolated olfactory precursors are specified by HH10, concomitant with their complete segregation from otherplacodal, epidermal and neural progenitors. Heterotopic transplantation of olfactory progenitors reveals they are capable ofautonomous differentiation only 12 hours later, shortly before overt placode invagination at HH14. Taken together, these resultsshow that olfactory placode development is a step-wise process whereby signals from adjacent tissues specify competent ectodermat or before HH10, followed by gradual commitment just prior to morphological differentiation. KEY WORDS: Olfactory placode, Nasal placode, Chick, Competence, Specification, Commitment, Induction, Ectoderm

21. Обонятельные рецепторы (хеморецепторы)

22. Обонятельные рецепторные нейроны (хеморецепторы)

23. Передача сигналов через обонятельные волоски (хеморецепторы)

24. The prevailing paradigm for G protein-coupled receptors is thateach receptor is narrowly tuned to its ligand and closely relatedagonists. • An outstanding problem is whether this paradigm appliesto olfactory receptor (ORs), which is the largest gene family in thegenome, in which each of 1,000 different G protein-coupled receptorsis believed to interact with a range of different odormolecules from the many thousands that comprise ‘‘odor space.’’ • Insights into how these interactions occur are essential for understandingthe sense of smell.

25. The vomeronasal organ (VNO), or Jacobson's organ, is an auxiliary olfactory sense organ that is found in many animals. It was discovered by Ludvig Jacobson in 1813. • During embryological development, it forms from the nasal (olfactory) placode at the anterior edge of the neural plate (cranial nerve zero). It is a chemoreceptor organ which is completely separated from the nasal cavity the majority of the time, being enclosed in a separate bony or cartilaginous capsule which opens into the base of the nasal cavity. It is a tubular crescent shape and split into two pairs, separated by the nasal septum. It is the first processing stage of the accessory olfactory system, after which chemical stimuli go to the accessory olfactory bulb, then to targets in the amygdala and hypothalamus.

26. Frontal section of nasal cavities of a human embryo 28 mm. long (Vomeronasal organ of Jacobson

27. The vomeronasal organ is mainly used to detect pheromones, chemical messengers that carry information between individuals of the same species, hence is sometimes referred to as the "sixth sense." The VNO has two separate types of neuronal receptors, V1R and V2R, which are seven-transmembrane receptors that are coupled to G proteins. The receptors are distinct from each other and form the large family of receptors in the main olfactory system. Evidence shows that the VNO responds to nonvolatile cues which stimulate the receptor neurons. Information is then transferred to the accessory olfactory bulb as well as other centres of the brain such as the anterior part of the hypothalamus.