Table 4. Examples of studies providing anatomically-specific information regarding the neural substrates of PPI, ca. 2001–2007.

1. Nucleus accumbens
2. Hippocampus
3. Prefrontal cortex
4. Entorhinal cortex
5. Amygdala
6. Dorsomedial thalamus
7. Habenula
8. Medial septum
9. Nucleus Basalis of Meynert
10. Inferior Colliculus
11. Pedunculopontine nucleus
12. Laterodorsal tegmental nucleus
13. Raphe complex
14. Brainstem

Reference	Rat strain, sex	Brain regions	Manipulation	Effect on PPI
		I. NAC
			Adults
Caceda et al. 2005	LE, M		Virally mediated increase in NT1 receptor	Blocked AMP & DIZ-induced PPI deficits
Culm et al. 2003	SD, M		Infusion of PTX	Blocked QUIN-induced PPI deficit
Culm et al. 2004	SD, M		Infusion of Sp-cAMP	Blocked QUIN-induced PPI deficit
Mohr et al. 2007	Mice, C3H, F		Infusion of DIH or QUIN	↑PPI after QUIN, but Ø PPI after DIH
Nagel et al. 2003	SD, M		Infusion of MSX-3 (A2 antagonist)	↓PPI
Pothuizen et al. 2005	WI, M	Core, shell	Infusion of muscimol	Loss of PP intensity dependency after infusion into NAC core but not shell
Pothuizen et al. 2006	WI, M	Core	NMDA-lesion of the NAC core	enhanced PPI disruption by DIZ but not APO
Powell et al. 2003	LE, F		Intra-NAC 6-OHDA in SR & IR rats	blocked ↓ in PPI in IR rats
Schwienbacher et al. 2002	SD, M	+ VTA	Infusion of DAergic, adenosinergic, or GABAergic compounds into NAC and/or VTA	↑PPI after combined VTA PTX + NAC SCH23390
Swerdlow et al. 2006d	SD, LE and F1 (SDxLE), M	+ Striatum	Measured DA-stimulated [35S]GTPγS-binding in NAC, striatum	PPI-APO sensitivity: SD>F1>LE. [35S]GTPγS-binding in NAC, striatum: LE>F1>SD
		II. HPC
			Adults
Ellenbroek et al. 2002,b	WI, M	CA1	Infusion of AMP, SKF81297 or QUIN	↓PPI after AMP, SKF81297 or QUIN; AMP-induced PPI deficits blocked by intra-NAC SCH23390 but not sulpiride
Ma and Leung 2004	LE, M	CA1	Electrical kindling	↓PPI (and ↓PA)
Finamore et al. 2001	Rats		Infusion of KA or NMDA antagonists	↓PPI with infusion of NMDA antagonists
Fitting et al. 2006a	SD, M		Infusion of viral toxin TAT	↑PPI (and ↓PA)
Inada et al. 2003	WI, M		Antisense NR1 knockdown	↓PPI with knockdown 6, but not 14d pre-testing
			Neonates
Fitting et al. 2006c	SD, M, F		Neonatal infusion of viral toxin gp120	↓PPI (and ↑PA); + Vehicle: ↓PPI with increasing gp120 doses. + APO: ↑PPI with increasing gp120 doses
Fitting et al. 2006b	SD, M, F		Neonatal TAT infusion	Males: ↓PPI at d 30 and 60, but not d 90
		vHPC
			Adults
Howland et al. 2004b	LE, M	+ dHPC	Electrical stimulation VHPC vs. DHPC combined with NAC microdialysis	↓PPI after VHPC but not DHPC stim.; ↑DA efflux: ipsi-but not contralateral NAC after unilateral stim. VHPC but not DHPC
Klamer et al. 2005b	SD, M		Microdialysis of the VHPC after systemic (or local) PCP	↓PPI and ↑cAMP after PCP; blocked by NO-synthase inhibitor L-NAME
Kusljic and van den Buuse 2004	SD, M	+ dHPC	5,7-DHT lesion	↓PPI for DHPC lesioned rats, and partially for VHPC lesioned rats
Zhang et al. 2002a	WI, M	+ dHPC	Infusion of NMDA	↓PPI after intra-VHPC but not-DHPC infusion
Swerdlow et al. 2004b	SD, M	+ FX	Infusion of NMDA into the VHPC in rats with EL lesions of the FX	↓PPI after NMDA infusion into VHPC, unaffected by FX lesion; IA lesion of the VHPC but not EL FX lesion enhanced ↓PPI by APO
			Neonates
Laplante et al. 2005	SD, M		IA-neonatal lesion	↓PPI; blocked by biperiden
Zhang et al. 2002b	WI, M	+ dHPC	Muscimol or TTX infusion	↓PPI, not blocked by HAL or CLO
Risterucci et al. 2005	SD, M		IA-neonatal lesion	↓PPI, ↓blood flow in NAC, BLA,VP, BNST, entorhinal–piriform and orbital CTX
			Adults
Caine et al. 2001	LH, M	dSUB or vSUB	QA-lesions	↓PPI after vSUB lesions. ↓PPI to AMP (not APO) after vSUB lesions.
		III. PFC
			Adults
de Jong and van den Buuse 2006	SD, M		Infusion of SCH23390	enhanced PPI deficits to APO but not DIZ
			Neonates
Grobin et al. 2006	M, F	+ MD	Neonatal elevation of allopregnanolone	↓PPI in castrates before and after puberty (PD20 and 80), but Ø PPI during puberty (PD40 and 60)
Rajakumar et al. 2004	SD, M		Neonatal infusion of antibody to the p75 neurtrophin receptor	↓PPI at age 10 wks, but not 5 wks
		mPFC
			Adults
Afonso et al. 2007	SD, F		NMDA-lesion	↓PPI
Bast et al. 2001	WI, M		Infusion of NMDA	↓PPI, not blocked by HAL or CLO
Day-Wilson et al. 2006	LH, M		IR (associated with ↓mPFC volume)	↓PPI
Schwabe and Koch 2004	WI, M		IA-lesion	lesion blocked DIZ-induced ↓PPI but not APO-induced ↓PPI
Shoemaker et al. 2005	SD, M		Infusion of SCH23390 into the mPFC; infusion of NMDA into the VHPC in rats with IA mPFC lesion	↓PPI after infusion of SCH23390 in mPFC; mPFC lesions block ↓PPI after intra-VHPC NMDA infusion
Swerdlow et al. 2006c	SD, M	+ NAC	Systemic SCH23390, IA lesion of mPFC, 6-OHDA DA depletion of mPFC or NAC	↓PPI after SCH23390, not blocked by either NAC DA depletion or mPFC lesion; ↓PPI after mPFC DA depletion
			Neonates
Schneider and Koch 2005	WI, M		IA-neonatal lesion	↑PPI in juveniles; enhanced PPI deficits to APO in adults
Schwabe et al. 2004	WI, M		IA-neonatal lesion	↑PPI after neonatal lesions; ↓PPI in both lesioned and intact rats after APO
		IV. eCTX
			Adults
Goto et al. 2002	WI, M		IA lesion	↓PPI, partially blocked by HAL
Goto et al. 2004	WI, M	+ NAC	eCTX lesion with IA, microdialysis of NAC	↓PPI, ↑DA concentration in NAC
Uehara et al. 2007	WI, M	+ mPFC	eCTX lesion with QA, mPFC lidocaine infusion	↓PPI after eCTX lesion or mPFC lidocaine
		V. AMY
			Neonatal
Daenen et al. 2003	F1 of WI/ UWU, M	AMY (or vHPC)	Neonatal AMY or VHPC lesions with IA	↓PPI in rats lesioned in the AMY or VHPC on d 7, but not on d 21
		BLA
			Adults
Howland et al. 2007	LE, M	+ eCTX, + vHPC	Electrical kindling	↓PPI shortly after kindling of BLA, but not of eCTX or VHPC
Kusljic and van den Buuse 2006	SD, M	+ CnA	5,7-DHT lesion	↓PPI with lesions of CnA but not BLA
Shoemaker et al. 2003	SD, M		QA lesion of the BLA	↓PPI, blocked by quetiapine
Stevenson and Gratton 2004	LE, M	+ Striatum	Infusion of SCH23390 or raclopride	↑PPI after intra-BLA SCH23390, ↓PPI after intra-BLA raclopride
		VI. MD
			Adults
Swerdlow et al. 2002c	SD, M		Infusion of QUIN or TTX	↓PPI after TTX but not QUIN, not blocked by quetiapine
		VII. Habenula
			Adults
Heldt andRessler 2006	Mice, C57, M		Electrolytic lesion	Ø PPI in the absence of stress; but ↓PPI after stress in habenula lesioned rats; blocked by CLO
		VIII. mS
			Adults
Ma and Leung 2007	LE, M	+ SUM	Infusion of muscimol	Muscimol into mS or SUM blocked ketamine-or DIZ-induced PPI deficits
Ma et al. 2004	LE, M		Infusion of muscimol	Infusion of muscimol into mS blocked PCP-induced PPI deficits
		IX. NBM
Ballmaier et al. 2002	SD, M		Immunolesion of cholinergic NBM neurons	↓PPI, blocked by single or repeated admin. of rivastigmine
		X. IC
			Adults
Silva et al. 2005	LE, M		Electrical stimulation	↓PPI
Sandner et al. 2002	SD, M	+ PnC	Evoked potentials from IC or PnC	↓PPI by ketamine and ↑evoked potentials
Yeomans et al. 2006	WI, M	SC, + intercollicular nuc. or PPTg	Electrical PP and pulses via electrodes to the SC, IC, intercollicular nucleus, or PPTg	PPI after electrical PP to most SC sites. Longer PPI latencies for electrical PP to the SC than IC, intercollicular nuc. or PPTg
		XI. PPTg
			Adults
Diederich and Koch 2005	WI, M		Infusion of muscimol	↓PPI at intervals≥120 ms
Takahashi et al. 2007	Mice, ICR, M	+ lGP, ssCTX	Infusion of phaclofen into the PPTg or lidocain into the lGP, c-fos labeling of brain regions after acoustic pulses or prepulses	↓PPI after intra-PPTg phaclofen or intra-lGP lidocaine; ↑c-fos in lGP after prepulses; ↑c-fos in NAC shell, PnC, and ssCTX after pulses, blocked in NAC and PnC by prepulses
		XII. LDTN, SN
			Adults
Jones and Shannon 2004	SD, M		IA-lesion of the LDTN or SN	↓PPI after lesion of LDTN but not SN
		XIII. DRN or MRN
			Adults
Kusljic et al. 2006	SD, M		5,7-DHT lesion	↓PPI in MRN but not DRN lesioned rats, blocked by HAL or CLO
Kusljic et al. 2003	SD, M		5,7-DHT lesion	↓PPI at all PP intensities for MRN-lesioned rats and for some PP intensities for DRN lesioned rats
		XIV. Brainstem
			Neonates
Shishkina et al. 2004	WI, M		Neonatal infusion of antisense oligonucleotide complementary to the α2 adrenoceptor	↓PPI at PD34, associated with ↑α2 adrenoceptors in HPC, AMY

AMP Amphetamine, AMY amygdala, APO apomorphine, BG background, BLA basolateral amygdala, BNST bed nucleus of the stria terminalis, C57 C57BL/6J, CLO clozapine, CnA central nucleus of the amygdala, CPA N(6)-cyclopentanyladenosine, CTX cortex, d dorsal, 5,7-DHT 5,7 dihydroxytryptamine, DIH dihydrexidine, DIZ dizocilpine, DRN dorsal raphe nucleus, e entorhinal, EL electrolytic, F females, FX fornix, HAL haloperdidol, HPC hippocampus, IA ibotenic acid, IC inferior colliculus, IR isolation rearing, KA kainic acid, l lateral, LDTN laterodorsal tegmental nucleus, LE Long Evans, LH Lister Hooded, M males, m medial, MD dorsomedial thalamus, MET methamphetamine, MRN median raphe nucleus, NAC nucleus accumbens, NBM nucleus basalis of Meynert, NMDA N-methyl-d-aspartate, NO nitric oxide, OVX ovariectomized, NT neurotensin, 6-OHDA 6-hydroxydopamine, PD postnatal day, PA pulse alone trial, PCP phencyclidine, PFC prefrontal cortex, PnC nucleus reticularis pontis caudalis, PPI prepulse inhibition, PPTg pendunculopontine nucleus, PTX pertussis toxin, QA quinolinic acid, QUIN quinpirole, S septum, SD Sprague–Dawley, SC superior colliculus, SN substantia nigra, Sp-cAMP cyclic adenosine monophosphate analogue, SR socially reared, ss somatosensory, SUB subiculum, SUM supramamillary area, v ventral, VP ventral pallidum, VTA ventral tegmental area, WI Wistar, ↓decreased, ↑ increased, Ø unchanged