1. OLFACTORY COMMUNICATION IN MAMMALS Mammalogy EEOB 625 9 February 2004

2. Olfactory Communication In Vertebrates Pheromone is a chemical released by one individual that elicits a response in one or more individuals of the same species Common in vertebrates except birds Source of chemical in the “sender” Chemosensory tissues in the “receiver” Criterion for pheromone status for a chemical? Effective in the absence of all other stimuli from the source individual

3. Sites of Pheromone Production Skin Glands: sternal, ano ‑ genital, hip, foot, pre ‑ orbital, tarsal, mandibular, chest Saliva and secretions of the oral angle gland Urine & feces (with preputial & anal glands) Examples: Castor canadensis ‑ castor & anal glands and the anal glands of mustelids

5. The mammalian skin: A major source of pheromones Epidermis: the pheromonally functional part of skin (dermis: the structural part) Derivatives of the epidermis Hair - guard hairs & underfur, vibrissae, follicles, piloerector muscles, and nerves Skin glands: 1. Sebaceous glands: oil glands of hair follicles 2. Eccrine ‑ sweat glands 3. Apocrine ‑ odor producing glands

6. Epidermis Dermis

7. Apocrine Ecrine Sebaceous

8. Chemoreception and the response to pheromones Olfactory epithelium of nasal turbinates & the main olfactory system – perception of odor External Nares & perception of direction Factors in sensitivity to odors & pheromones Vomeronasal organ (Jacobson's Organ) Sensitive to both volatile and non-volative chemeicals Important in detection of sex pheromones Flehmen behavior in ungulates

9. Typical Mammal Human

10. (VNO) Vascular sinus

11. Properties & Types of Pheromones Chemical Properties: volatile & non-volatile compounds: e.g., amines, carboxylic acids, & fatty acids (important?) Signaling pheromone – Definition & examples: Broadcast scent marking ‑ "territorial" & individual and Family recognition Sexual attractants: estrous females Priming pheromone: definition & examples: Reproductive activation: puberty & estrous cycles Response to pheromones: hypothalamus, pituitary, & ? Reproductive activation in the gray short-tailed opossum

13. Pheromonal Activation of Reproduction in Female Opossums Females in estrus

14. Supra-sternal gland of male opossum

15. Phermomonal Induction of Puberty in Opossums Pheromonal Exposure (from 90 days) Direct Indirect Isolated N 22 22 12 Estrus 22 13 0 Days at Estrus 127 162 ( none at 180) Weight (g) 61 59 ( 61, nonestrus ) at 1 st Estrus Stonerook & Harder (1992)

16. Juvenile body weight Ovarian follicle diameter