Emission of the maternal pheromone in nulliparous and lactating females

Emission of the Maternal Pheromone in Nulliparous and Lactating Females’

that on Day 1 of maternal behavior the Icmalc‘ wa> caring for young which were 7 days of ap. on I)ay .7. for young .: days of age, and so on. t’cmales or their feces alone were tested in the olt’actor~ discrimination apparatus dcscrihcd hy Leon and Molt/ 101 This apparatus permits pups to approach tither of two ~O:II boxes across a triangular field from a start box. Opaque’ Plexiglas prcvcnts the contents of the goal hoxcs from hc~ng visible from the open field. The pups rcgistcr ;I choiiz h> descending a small cliff into rithcr goal box. Filicrcd ‘III from a single overhead valve is forced to flow through tltc goal compartments up through the cliff-opening inter f ht. open area of the apparatus and thrn to the start box. All test pups and stimulus animals were isolated from other animals for 3 hr prior to tosting. A single pup ~‘34 placed in the start hox and allowed IO min in which 10 make a choice. After each pup registttrcd a choice, or when IO min had elapsed, it was rcmovetl from the apparatu’r and the absorbent paper covering the open ficltl and the start box was rcplaccd. After .3 pups had been run. the animals or their feces wcrt’ removed and the apparatus wab thoroughly washed with warm water and dried. The goal hos positions of the stimulus animals or their fcccs uerc‘ then reversed. A total of 6 pups was run against l!ilCtl palrcll conihination. Thr pups themsclvcs wc‘rc‘ lo days 01 ;I~I’. XICCICLI hccausc it is known that such pups respond strongly to the maternal phcromonc [ 0.7 1 Fvcry pup uwl in I Iwc cxpcriments was tMcit for 3 prefercncc only once. \onc (11 the pups used had hecn in previous association with an! stimulus animal.

W 0 m

21 days I,I(;.

Feces of concaveoted-maternal females Feces of non-concaveated females No choice

after

onset

of maternal

behavior

I. Kc\pon\c 01’ \t;lnd;lrd I6-da) -old ~III_” IO (c’cc\ 01 c’cln~~;lve:itedt’cIIl;tlcs vs. lC~.c\ of nclnconcaveatedI’cinales.

In this cxpcriment our goal was lo determIne whcthcr the phcromonc of the concaveated Inatcrnal fcmalc wab actually located in her feces since it was possible that the pups wcrc transmitting the pheromone from their biological mothers to their nulliparous foster mothers. A group of IO nulliparous females was formed and exposed to young irl the manner described ahove. When the concavrated females had been behaving maternally for 7 I days, their feces wc’rc taksn and tested against feces of nonconcaveatrcl females. (‘arc’ was exercised to collect the same number of lccal holi from cdch animal. The data in I-ig. I indicate the pr~scncs of the phcromonc in the feces of the concaveatcd Inatcrnal fcmalcs. Statistical analysis confirms this by showing that pups overwhelmingly chose the compartment containing the fcccs of the concavcated maternal female ty’ . pcO.001 ). Such evidence eliminates the possibility that the pups were transmitting the pheromone to their concavcated foster mothsrs.

WC then wanted to determine whether the pheromone ot the concaveated maternal female could be distinguished from the pheromone of the lactating female. TO accomplish this, feces taken from IO concaveated maternal females were tcstcd against feces taken from ten 21 day lactating females. ~rhese lactating females were known to be emitting the pheromone. As in Experiment I, the tests began 2 I days after the concaveated females began to behave maternally.

50

-1 ,

sm

40.

m n m

Feces of concavroted-moternaI females Feces of 21-day lactating females No choice

I

1

.0 0’ EJ 30. n. + 0 k

20-

$ 1 10

21 days after

onset

of maternal

behavior

Hcrc we wt‘rc‘ intrrested In the question of whether Ihe pheromone of the concaveated maternal female is under prolactin control. as it is in the lactating female. To answt‘l

That

emitting of the controls

the

concaveated maternal females were actualIS a pheromone can be seen from the fact that 75’:; pups preferred such females over nonconcaveated (xz : p
Recent evidence 141 has indicated the existance of ;I pheromone emitted by the maternally behaving nulliparous female. This attractant was hypothesized to be identical to that found in the lactating female. The data reported here

support this hypothesis in showing that (a) the pheromom of the concaveated-maternal female is carried in her feces.

REFERENCES

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5.

J.. J. Dan, C;. 0. Sudarshan and J. H. Anderson. ‘I’hc intlucncc of nutrition on neural and behavioral development. II. Growth of body and brain in infant rats using different techniques of under-nutrition. lkvi Prwhohid. 4: SC 711. 1971. (‘ok, II. H. and C;. H. Hart. The cl’l’cct of pregmancy .~nd IJctation on growth in the rat. .4v1. .I. PI~~~siol.123: 589.. 597. 1938. (‘ores. P. M. and H. A. C‘ro
Altman.

0. 7. X.

9.

II).

II

I.COII. \I. .~ntf II. Molt/. hlcr~lcrl ;wcrom~1nc. ~il~irllllinif11~,1! hy prcweanling albino r;lts. Plr~siol. H~lro~. 7: 265 267. IO71 1 con. \I. and H. Moltz. The dcvcI~~pmcnt 01 IIIL’ phcrom~m:il Ix~nd in rho albino rat. P/I,Iw’v/. fIt,/!o:. 8: 6X3 6X6. 1972. Ixon. %I. and I-1. Molr~. tndoa-IIIL, confr~ll (II’ ths ina!crn:ll I‘hcrcrmonc in the postpartum ~~~m;~lcWI P/~~~sio!. Hciw~~ IO: 65 67, 1973. Mcnakcr. I and J. 31. Sav~a. ,\ppct~tc rcgul,lticln 11, 111~.r;11 ~lndcr v,irious physiological iondltlun\: ‘l’hc n)lc (\I‘ d~cr;~r! pr0tctn and calories. J. .VLtrr. 103: .7_)7 352. 197.:. I n,hrl~n> in IIIC bch.l\lur;li interaction hctwc‘cn the morher .~nd her c>f’fsprln; 111 ~hc 13bor;llory ral. In: lIrrcw7fit7c7r~rsI):’ ItiJatrr Hdm~~iolrr. \‘~>l. 3. cd~tcd hy 13. M. l:oss. Ne\\,York: Wllcv. 1965. pp. 3 1 I \Vie